----------------------------------------------------------
3-Prime-Deoxyribonucleotide
Nucleotide at the end of a DNA sequence which is connected
within the sequence only at the 5' OH. At the end of a
molecule the 3'-OH is free. Souther.
----------------------------------------------------------
----------------------------------------------------------
3-Prime-End
The region of a nucleic-acid which includes the
terminal nucleotide with a free 3' hydroxyl group.
Souther.
----------------------------------------------------------
----------------------------------------------------------
3-Prime-Nucleotide
Nucleotide at the end of a sequence whose 3' end either
bears a free hydroxyl group (free sequences like DNA
strands or DNA strand fragments) or whose 3' end
is attached to a neighboring sequence (internal sequences
like introns or regulatory sequences). Souther.
----------------------------------------------------------
----------------------------------------------------------
3-Prime-Ribonucleotide
Nucleotide at the end of a RNA sequence which is connected
within the sequence only at the 5' OH. At the end of a
molecule the 3'-OH is free. Souther.
----------------------------------------------------------
----------------------------------------------------------
5-Prime-Deoxyribonucleotide
Nucleotide at the end of a DNA sequence which is connected
within the sequence only at the 3' OH. If at the end of
a molecule the free 5' OH is connected to a triphosphate
rather than a monophosphate. Souther.
----------------------------------------------------------
----------------------------------------------------------
5-Prime-End
The region of a nucleic-acid which includes the
terminal nucleotide with a free 5' triphosphate group.
Souther.
----------------------------------------------------------
----------------------------------------------------------
5-Prime-Nucleotide
Nucleotide at the end of a sequence whose 5' end either
bears a free triphosphate (free sequences like DNA strands
or DNA strand fragments) or whose 5' end
is attached to a neighboring sequence (internal sequences
like introns or regulatory sequences). Souther.
----------------------------------------------------------
----------------------------------------------------------
5-Prime-Ribonucleotide
Nucleotide at the end of a RNA sequence which is connected
within the sequence only at the 3' OH. If at the end of
a molecule the free 5' OH is connected to a triphosphate
rather than a monophosphate. Souther.
----------------------------------------------------------
----------------------------------------------------------
7-Methyl-Guanosine
A modified guanosine which is attached to
the 5' end of newly made mRNA during RNA
capping. Alberts:ECB:218.
----------------------------------------------------------
----------------------------------------------------------
A-Site
The site on the ribosome where the incoming amino-acyl
tRNA binds. Alberts:ECB:230.
----------------------------------------------------------
----------------------------------------------------------
ADP
Nucleoside that is produced by hydrolysis of the
terminal phosphate of ATP. Alberts:ECB:G-1
----------------------------------------------------------
----------------------------------------------------------
AMP
Adenosine monophosphate. One of the four nucleotides
in RNA. AMP is produced by the energetically
favorable hydrolysis of ATP. Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
ATP-Synthase
Membrane-associated enzyme complex that catalyzes the
formation of ATP during oxidative phosphorylation and
photosynthesis. Found in mitochondria, chloroplasts,
and bacteria. Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
ATP-Synthesis
The production of a more complex substance
from simpler substances by a living entity.
Souther, 2001.
----------------------------------------------------------
----------------------------------------------------------
ATP
Adenosine triphosphate.
The principle carrier of chemical energy in cells.
The terminal phosphate groups are highly reactive in
the sense that their hydrolysis, or transfer to
another molecule, takes place with release of a large
amount of free energy. Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
Acetamino-Group
A chemical group derived from acetamine.
CH3-CONH2. Souther.
----------------------------------------------------------
----------------------------------------------------------
Acetyl-Group
A chemical group derived from acetic acid.
Alberts:ECB:G-1
----------------------------------------------------------
----------------------------------------------------------
Acid-Substance
Substance that dissociates in water to release protons
(H+ ions) thereby producing a low pH; these protons
associate with water, generating hydronium (H3O+) ions.
Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Acid
Molecule (or substance) that dissociates in water to
release one or more protons (H+ ions).
see Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Acidic-Amino-Acid
An amino acid which carries a net negative charge at
pH 7. Souther.
----------------------------------------------------------
----------------------------------------------------------
Actin-Filament
Protein filament, about 7nm thick, formed from a
chain of globular actin molecules. A major
constituent of the cytoskeleton of all eucaryotic cells
and especially abundant in muscle cells.
Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Actin-Molecule
A globular protein that polymerizes into actin
filaments. see Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Activate
To put into a state where it a can participate in an
action. Souther.
----------------------------------------------------------
----------------------------------------------------------
Activated-Carrier
Small molecule carrying a chemical group in a
high-energy linkage, serving as a donor of energy or of
the chemical group in may different chemical reactions.
Examples include ATP, acetyl CoA, and NADH.
Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Activation-Energy
Extra energy that a molecule must acquire
in order to surmount an energy barrier so
as to undergo a particular chemical
reaction. Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Active-Site
Region of an enzyme surface to which a substrate
molecule binds before it undergoes a catalyzed
reaction. Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Add-Enzymatic
The enzymatic addition of a group to an atom or
molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Addition-Enzyme
Enzyme that adds a group to an atom or molecule.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Adenine
A purine base which combines with a ribose base to form
adenosine. Adenosine phosphates are prominent
molecules in cells as ATP, cAMP, and nucleotides.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Adenosine
A nucleoside containing adenine that when joined
with a monophosphate group forms one of the four
nucleotides in RNA. As a nucleoside triphosphate
it is the principle energy yielding molecule in
the cell. Souther.
----------------------------------------------------------
----------------------------------------------------------
Alanine
A nonpolar amino acid with a methyl side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Alcohol
Organic compound containing a hydroxyl group bound
to a saturated carbon atom - for example ethyl
alcohol. Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Allosteric-Enzyme
Enzyme that exists in two or more
conformations depending on the binding of a molecule
[a ligand] at a site other than the catalytic site.
Allosteric enzymes composed of multiple subunits often
display a cooperative response to ligand binding.
Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Allosteric-Protein
Protein that exists in two or more conformations
depending on the binding of a molecule (a ligand) at a
regulatory site. Allosteric proteins composed of
multiple subunits often display a cooperative response
to ligand binding. Modified from Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Alpha-Carbon
The central carbon atom in an alpha amino acid, to
which the carboyxl and amino groups and the side chain
group are attached. Souther.
----------------------------------------------------------
----------------------------------------------------------
Amido-Group
Molecule containing a carbonyl group linked to an
amine. Alberts:ECB:G-1.
----------------------------------------------------------
----------------------------------------------------------
Anion
A negatively charged ion. Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
Amino-Acid-Binding-Site
A short, single-stranded region at the 3' end of
TRNA where the amino acid that matches the codon of
the mRNA being translated is bound.
see Alberts:ECB:226.
----------------------------------------------------------
----------------------------------------------------------
Amino-Acid-Sequence
A chain of amino-acids linked by peptide bonds.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Amino-Acid-Side-Chain
A chemical group which is attached to the alpha
carbon in alpha amino acids. For living
organisms, there are about 20 different side
chains yielding 20 different amino acids which
make up proteins. Souther.
----------------------------------------------------------
----------------------------------------------------------
Amino-Acid
Organic molecule containing both an amino group and a
carboxyl group. Alpha amino acids (those in which the
amino and carboxyl groups are linked to the same
carbon atom) serve as the building blocks of proteins.
Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
Amino-Acyl-TRNA-Synthetase
An enzyme that adds one of the amino acids to the
end of the appropriate tRNA molecule before the tRNA
binds to the ribosome during mRNA translation.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Amino-Group
Weakly basic functional group, derived from
ammonia (NH3). In aqueous solution an amino
group can accept a proton and carry a positive
charge. Alberts:ECB:G-2
----------------------------------------------------------
----------------------------------------------------------
Amino-Terminus
That end of a polypeptide chain which carries an
unattached amino acid group. Alberts:ECB:G-12
----------------------------------------------------------
----------------------------------------------------------
Amoeboid-Cell-Locomotion
The finger-like locomotion of a cell caused by the
projection and retraction of internal actin
filaments. Souther.
----------------------------------------------------------
----------------------------------------------------------
Aqueous-Solution
A solution in which water is the solvent for dissolved
particles. Souther.
----------------------------------------------------------
----------------------------------------------------------
Arginine
A basic amino acid with a di-amido propylamine side
chain CH2CH2CH2NHCH(NH2)2 Souther
----------------------------------------------------------
----------------------------------------------------------
Aromatic-Compound
A ring compound containing the benzene
ring. Souther.
----------------------------------------------------------
----------------------------------------------------------
Asparagine
A polar amino acid with a acetamino side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Aspartic-Acid
A polar amino acid with a acetic side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Atom
The smallest particle of an element that still retains
its distinctive chemical properties.
Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
Attach-Enzymatic
The attachment or addition of a group to a molecule,
such as a phosphate, amino group, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Bacterium
Member of one of the two classes of procaryotes,
the other group being the archaea. Souther.
----------------------------------------------------------
----------------------------------------------------------
Bacterial-DNA
Double-stranded polynucleotide formed from two
separate chains of deoxyribonucleotide units;
serves as the carrier of genetic information in
bacteria. Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Bacterial-RNA-Polymerase
Enzyme that catalyzes the synthesis of an
RNA molecule on a DNA template from nucleoside
triphosphate precursors in bacteria.
(modified from Alberts: ECB:G-16).
----------------------------------------------------------
----------------------------------------------------------
Bacterial-RNA-Transcript
RNA product of DNA transcription in bacteria.
Alberts:MBC:1994.
----------------------------------------------------------
----------------------------------------------------------
Base-Pair
Two nucleotides in an RNA or a DNA molecule that are
paired by hydrogen bonds - for example, G with C, and A
with T or U. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Base
Molecule or substance that accepts proton(s) in
solution. Also used refer to the purines and
pyrimidines in DNA and RNA. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Basic-Amino-Acid
An amino acid which carries a net positive charge at
pH 7. Souther.
----------------------------------------------------------
----------------------------------------------------------
Benzene
A six-carbon ring with the carbons attached to each
other by conjugated double bonds. Souther.
----------------------------------------------------------
----------------------------------------------------------
Binding-Site
Region on the surface of a molecule - typically a
cavity or groove - that is complementary in shape to
another molecule (the ligand) and therefore can bind it
through the formation of multiple weak (noncovalent)
bonds. cf Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Biological-Kingdom
Highest biological taxonomic category. Organisms have
been classically divided into 5 kingdoms. Souther.
----------------------------------------------------------
----------------------------------------------------------
Biological-Membrane
Thin sheet of lipid molecules and associated proteins
that encloses all cells and forms the boundaries of
many eucaryotic organelles. Alberts:ECB:G-11 as
'membrane'.
----------------------------------------------------------
----------------------------------------------------------
Biosynthesize
The production of a more complex substance
from simpler substances by a living entity.
Souther, 2001.
----------------------------------------------------------
----------------------------------------------------------
Bound-Ribosome
Ribosomes that are bound to the endoplasmic reticulum.
Areas with bound ribosomes are called rough endoplasmic
reticulum. Souther.
----------------------------------------------------------
----------------------------------------------------------
Butyl-Group
Hydrophobic chemical group derived from butane.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Butylamine
Amine derived from butane. CH3-CH2-CH2-CH2-NH3.
Souther.
----------------------------------------------------------
----------------------------------------------------------
CMP
Cytidine monophosphate. One of the four nucleotides
in RNA and DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
CTGGCGGC-Like-Sequence
A DNA consensus sequence that forms part of the terminator
for DNA transcription. Alberts:ECB:217.
----------------------------------------------------------
----------------------------------------------------------
CTP
Nucleoside triphosphate used in the synthesis of
RNA and DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Carbohydrate
General term for sugars and related compounds with
the general formula (CH2O)n. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Carbon-Atom
The fundamental building block of living systems.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Carbon-Dioxide
Chemical group consisting of a carbon atom linked
to two oxygen atoms by covalent bonds.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Carbonyl-Group
Chemical group consisting of a carbon atom linked
to an oxygen atom by a double bond.
Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Carboxyl-Group
Chemical group consistingt of a carbon atom linked
both to an oxygen atom by a double bond and to a
hydroxyl group. Molecules containing a carboxyl
group are weak acids (carboxylic acids).
Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Carboxyl-Terminus
That end of a polypeptide chain which carries an
unattached carboxylic acid group. Alberts:ECB:G-3
----------------------------------------------------------
----------------------------------------------------------
Carboxylic-Acid
Organic compounds containing the carboxy group
(-COOH). This group of compounds includes amino acids
and fatty acids. Carboxylic acids can be saturated,
unsaturated, or aromatic. PubMed:MeSH.
----------------------------------------------------------
----------------------------------------------------------
Catabolic-Enzyme
An enzyme involved in the breakdown of large molecules
into smaller accompanied by the release of energy.
Souther (see Alberts:ECB:G-3 on catabolic).
----------------------------------------------------------
----------------------------------------------------------
Catabolize
Cellular process whereby complex molecules are
degraded to simpler ones and energy is released.
Lodish:MCB:G-2.
----------------------------------------------------------
----------------------------------------------------------
Catalysis
A chemical reaction whose rate is facilitated by
the presence of a substance which is not altered
by the reaction. Souther.
----------------------------------------------------------
----------------------------------------------------------
Catalyst
A molecule that accelerates a chemical reaction without
itself undergoing a change. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Cation
A positively charged ion. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Cell-Locomotion
The locomotion of a cell, usually accomplished
internally using actin filaments or externally
using flagella or cilia. Souther.
----------------------------------------------------------
----------------------------------------------------------
Cell-Wall
Mechanically strong fibrous layer deposited by a cell
outside its plasma membrane. Prominent in most plants,
bacteria, algae, and fungi but not present in most
animal cells. Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Cell
The basic unit from which living organisms are made,
consisting of an aqueous solution of organic molecules
enclosed by a membrane. All cells arise from existing
cells, usually by a process of division into two.
(Alberts:ECB:G-3).
----------------------------------------------------------
----------------------------------------------------------
Cellular-Respiration
The process by which glucose is broken down to
CO2 and water. Normally, ATP is generated in the
process. Substages include glycolysis, citric acid
cycle, and oxidative phosphorylation. Souther.
----------------------------------------------------------
----------------------------------------------------------
Cellulose
Structural polysaccharide consisting of long chains of
covalently linked glucose units. It provides tensile
strength in plant cells. Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Centriole
Short cylindrical array of microtubules, usually found
(in animal cells in a paired arrangement at the center
of a centrosome. Similar structures are found at the
base of cilia and flagella, where they are called basal
bodies. Alberts:ECB:G-4
----------------------------------------------------------
----------------------------------------------------------
Centrosome
Centrally located organelle of animal cells that is the
primary microtubule-organizing center and is
duplicated to form the spindle poles during mitosis.
In most animal cells it contains a pair of centrioles.
Alberts:ECB:G-4
----------------------------------------------------------
----------------------------------------------------------
Charged-Polar-Amino-Acid
A polar amino acid bearing a charge. Souther.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Bond-Energy-Transfer
The transfer of chemical energy from one molecule to
another. Souther.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Bond-Energy
The strength of the chemical linkage
between two atoms, measured by the energy
in kilocalories/mole needed to break it.
Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Bond
Linkage between two atoms that holds them together
in a chemical compound. Types found in living
cells include ionic bonds, covalent bonds, polar
bonds, and hydrogen bonds. Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Entity
Any molecule, atom, substance, or phenomenon (e.g,
a chemical bond) which has chemical properties.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Energy-Transfer
The transfer of chemical energy from one entity to
another. Souther.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Energy
Energy produced by or stored in chemical
properties or property differentials, such as
chemical bonds, such as charge gradients,
density gradients, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Cistron
The smallest unit of DNA that must be intact to code
for the amino acid sequence of a polypeptide; thus,
the coding part of a gene, minus 5' and 3' untranslated
sequences and regulatory elements. Matthews:BC:1150.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Group
Set of covalently linked atoms, such as a hydroxyl
group or an amino group, tht occurs in many
different molecules and has a distinctive chemical
character. Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Mixture
An aggregate of two or more substances that are not
chemically united and that exist in no fixed
proportion to each other. RHCD:856.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Object
Any object which is typically described in terms
of its chemical properties. Includes atoms,
molecules, and chemical groups like methyl group.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Sequence
A sequence of monomers that form a chain, e.g.
polymers. Souther:2001
----------------------------------------------------------
----------------------------------------------------------
Chemical-Solution
The homogeneous mixture of a solid, liquid, or gas
within a liquid or sometimes a solid or gas.
WNCD:1123.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Substance
A substance composed of atoms or molecules.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Chromatin
Complex of DNA, histones, and nonhistone proteins found
in the nucleus of a eucaryotic cell. The material of
which chromosomes are made. Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Chromosome
Long, threadlike structure composed of DNA and
associated proteins that carries part or all of the
genetic information of an organism. Alberts:ECB:G-4
----------------------------------------------------------
----------------------------------------------------------
Citric-Acid-Cycle
Central metabolic pathwya in all aerobic organisms
that oxidizes acetyl groups derived from food
molecules to CO2. In eucaryotic cells these
reactions are located in the mitochondrial matrix.
Alberts:ECB:G-4.
----------------------------------------------------------
----------------------------------------------------------
Coding-Sequence
A DNA or RNA sequence which contains genetic
information, encoded in nucleotide triplets, termed
codons. Souther.
----------------------------------------------------------
----------------------------------------------------------
Codon
Sequence of three nucleotides in DNA or mRNA that
represents the instruction for incorporation of a
specific amino acid into a polypeptide chain.
Alberts:ECB:G-5.
----------------------------------------------------------
----------------------------------------------------------
Coenzyme
Small molecule tightly associated with an enzyme
that participates in the reaction that the enzyme
catalyzes, often by forming a transient covalent
bond to the substrate. Examples include biotin,
NAD+, and coenzymeA. Alberts:MBC:G-6
----------------------------------------------------------
----------------------------------------------------------
CoenzymeA
Small molecule used in the enzymatic transfer of
acyl groups in the cell. Alberts:ECB:G-5
----------------------------------------------------------
----------------------------------------------------------
Collagen
A fibrous protein rich in glycine and proline that is
a major component of the extracellular matrix in animal
tissues. Exists in many forms: type I, the most common,
is found in skin, tendon, and bone; type II is found in
cartilage; type IV is present in basal laminae.
Alberts:ECB:G-5.
----------------------------------------------------------
----------------------------------------------------------
Colloid
A mixture of a solid, liquid, or gas that does not
in a solid, liquid, or gas that does not separate
out upon standing, such as an emulsion, foam,
smoke, or fog. RHCD:264 cf colloidal system.
----------------------------------------------------------
----------------------------------------------------------
Compound-Protein
A protein made up of polypeptide subunits held
together by noncovalent bonds. The structure formed
by these subunits is called quaternary structure.
Examples include microtubules, hemoglobin. Souther.
----------------------------------------------------------
----------------------------------------------------------
Conjugated-Double-Bond
A double bond which exists in alteration with single
bonds in a carbon skeleton. WHS:PBC-5th:61.
----------------------------------------------------------
----------------------------------------------------------
Covalent-Bond
A stable chemical link between two atoms produced by
sharing one or more electrons. Alberts:ECB:G-5
----------------------------------------------------------
----------------------------------------------------------
Covalent-CC-Bond
Chemical bond between two carbons. Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-CH-Bond
Chemical bond between carbon and hydrogen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-CN-Bond
Chemical bond between carbon and nitrogen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-CO-Bond
Chemical bond between a carbon and a oxygen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-CS-Bond
Chemical bond between a carbon and a sulfur.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-NH-Bond
Chemical bond between hydrogen and nitrogen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-PO-Bond
Chemical bond between a phosphorus and a oxygen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Covalent-Single-Bond
A stable chemical link between two atoms produced by
sharing a pair of electrons. cf Alberts:ECB:G-5
----------------------------------------------------------
----------------------------------------------------------
Cysteine
A nonpolar amino acid with a Thiol-methyl side
chain. Souther
----------------------------------------------------------
----------------------------------------------------------
Cytidine
A nucleoside containing cytosine that when joined
with a monophosphate group forms one of the four
nucleotides in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Cytoplasm
Contents of a cell that are contained within
the plasma membrane, but, in the case of
eucaryotic cells, outside of the nucleus.
Alberts:ECB:G-5
----------------------------------------------------------
----------------------------------------------------------
Cytoplasmic-Protein
A protein located in the cytoplasm of the cell.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Cytosine-Deamination
The loss of an amino group from a cytosine base
in a DNA molecule.
Souther, see Alberts:ECB:202.
----------------------------------------------------------
----------------------------------------------------------
Cytosine
A pyrimidine base which combines with a ribose base to
form cytosine. Cytosine triphosphates are one of the
building block monomers for DNA and RNA.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Cytoskeleton
System of protein filaments in the cytoplasm of a
eucaryotic cell that gives the cell a polarized shape
and the capacity for directed movement. Its most
abundant components are actin filaments, microtubules,
and intermediate filaments. Alberts:ECB:G-5.
----------------------------------------------------------
----------------------------------------------------------
Cytosol
Aqueous solution of large and small molecules that
fills the main compartment of the cytoplasm. Excludes
membrane-bounded organelles such as endoplasmic
reticulum and mitochondria. Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
D-AMP
Deoxyadenosine monophosphate. One of the four nucleotides
in DNA, containing deoxyribose and adenine. Souther.
----------------------------------------------------------
----------------------------------------------------------
D-CMP
Deoxycytidine monophosphate. One of the four nucleotides
in DNA, containing cytosine and deoxyribose. Souther.
----------------------------------------------------------
----------------------------------------------------------
D-GMP
Deoxyguanosine monophosphate. One of the four nucleotides
in DNA, containing deoxyribose and guanine. Souther.
----------------------------------------------------------
----------------------------------------------------------
D-TMP
Deoxythymidine monophosphate. One of the four nucleotides
in DNA, containing deoxyribose and thymine. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Codon
Sequence of three nucleotides in a DNA molecule that
represents the instruction for incorporation of a
specific amino acid into a polypeptide chain.
cf Alberts:ECB:G-5 (codon).
----------------------------------------------------------
----------------------------------------------------------
DNA-Coding-Sequence
A region of the DNA which codes for all or part of a
protein or RNA. It may include noncoding regions,
as for example in eucaryotic genes which include
regulatory sequences. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Molecule
Double-stranded polynucleotide formed from two separate
chains of deoxyribonucleotide units; serves as the
carrier of genetic information. Alberts:ECB:G-6
----------------------------------------------------------
----------------------------------------------------------
DNA-Gene-Coding-Sequence
Physical and functional unit of heredity, which carries
information from one generation to the next. In
molecular terms, it is the entire DNA sequence -
including exons, introns, and noncoding transcription
control regions - necessary for production of a
functional protein or RNA. (Lodish:MCB:G-7).
Note: this is the definition for gene, but applies to
operons as well.
----------------------------------------------------------
----------------------------------------------------------
DNA-Gyrase
A protein which binds to DNA and relieves torsional
strain generated by DNA unwinding during replication.
see Lehninger:PBC:943
----------------------------------------------------------
----------------------------------------------------------
DNA-Helicase
An enzyme that catalyzes the separation of strands in
a DNA molecule before replication. Lehninger:PBC:G-6
----------------------------------------------------------
----------------------------------------------------------
DNA-Ligase
An enzyme that appends nucleotides onto the growing
DNA chain during chain elongation or joins two
nucleotide sequences together during repair of strand
breaks. Souther. see Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
DNA-Ligation
The joining of the 3' end of one nucleic acid strand with the
5' end of another, forming a continuous strand. see
Lodish:MCB:G-10. definition for ligase.
----------------------------------------------------------
----------------------------------------------------------
DNA-Mismatch-Repair-Protein
Enzyme that helps repair mismatches in DNA base pairs
by removing a sequence which includes the mismatched
pairs. Souther. see Alberts:ECB:200-201.
----------------------------------------------------------
----------------------------------------------------------
DNA-Mismatch-Repair
A DNA repair system that identifies base pair
mismatches, excises a region of the DNA strand
containing the mismatch(es), and resynthesizes the
missing nucleotide pairs. Paraphrased from
Alberts:ECB:200.
----------------------------------------------------------
----------------------------------------------------------
DNA-Repair
Collective term for the enzymatic processes
that correct deleterious changes affecting
the continuity or sequence of a DNA
molecule. Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
DNA-Non-Coding-Region
A region which does not code for RNA or proteins.
Examples include the spacer DNA regions in
eucaryotes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Information
Knowledge communicated or received concerning a
particular fact or circumstance. RHCD:1st Revised:
684.
----------------------------------------------------------
----------------------------------------------------------
DNA-Noncoding-Sequence
A region of the DNA which does not code for any known
product, either protein or RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Polymerase-Repair
Enzyme that catalyzes the repair of a DNA
molecule either because of damage or because
of wrong base incorporation. Also used to
replace the RNA primer during DNA replication.
Souther. see Alberts:ECB:196.
----------------------------------------------------------
----------------------------------------------------------
DNA-Polymerase-Replication
Enzyme that catalyzes the synthesis of a DNA
molecule on a DNA template from nucleoside
triphosphate precursors. Alberts: ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
DNA-Polymerase
Enzyme that catalyzes the synthesis or repair
of a DNA molecule from nucleoside triphosphate
precursors using a DNA template. Souther. see
Alberts: ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
DNA-Regulatory-Protein
A protein that regulates DNA replication or gene
expression. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Regulatory-Region
A region of the DNA that contains regulatory sequences.
Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Regulatory-Sequence
A sequence of DNA deoxyribonucleotides on a DNA strand
that regulates the replication or transcription
of DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Replication
A process by which a copy of a DNA molecule is made.
Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Diphosphate
A compound containing a two phosphate groups in a chain,
linked by phosphoanhydride bonds. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Sequence
A nucleotide sequence of deoxyribonucleotides.
Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Strand
One of two complementary anti-parallel chains that make
up the DNA double helical molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Synthesis
A process by which a copy of all or part of a DNA
molecule is made. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Template
A DNA sequence which is copied during DNA
replication or repair.
----------------------------------------------------------
----------------------------------------------------------
DNA-Transcription
Copying of one strand of DNA into a complementary RNA
sequence by the enzyme RNA Polymerase.
Alberts:ECB:1998.
----------------------------------------------------------
----------------------------------------------------------
DNA-Virus
A virus which contains DNA (cf RNA Virus whose
particles contain RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Damaged-DNA-Repair
A DNA repair system that identifies DNA damaged
by environmental stimuli, such as UV radiation
and repairs it. Souther, see Alberts:ECB:204.
----------------------------------------------------------
----------------------------------------------------------
Damaged-DNA-Sequence
A region of the DNA which has missing, mismatched, or
altered bases or base pairs. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deaminase
Enzyme that removes an amino group from a
molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deamination
The loss or removal of an amino group from a
molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxyadenosine
A nucleoside containing adenine and deoxyribose that
when joined with a monophosphate forms one of the four
nucleotides in DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxycytidine
A nucleoside containing cytosine and deoxyribose that
when joined with a monophosphate group forms one of
the four nucleotides in DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxyguanosine
A nucleoside containing guanine and ribose that
when joined with a monophosphate forms one of the four
nucleotides in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxyribonuclease
Enzyme that cleaves DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxyribonucleotide
Nucleotide containing 2-deoxy-D-ribose as the pentose
component. Lehninger:PBC:G-3.
----------------------------------------------------------
----------------------------------------------------------
Deoxyribose
A pentose which forms the carbohydrate moiety of
nucleotides which constitute DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxythymidine
A nucleoside containing thymine and deoxyribose that
when joined with a monophosphate group forms one of
the four nucleotides in DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Dephosphorylation
The removal of a phosphoryl group from a molecule.
The resulting molecule is less charged energetically
and is said to be deactivated. Souther.
----------------------------------------------------------
----------------------------------------------------------
Depurination
The spontaneous loss of a purine from a DNA
strand. Souther, see Alberts:ECB:202.
----------------------------------------------------------
----------------------------------------------------------
Detach-Enzymatic
The removal of a group from a
molecule, such as a phosphate, amino
group, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Diffuse
The spread of molecules and small particles from one location
to another through random, thermally-driven movements.
Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Dinitrogen
Molecule made up of two covalently bonded nitrogen
atoms. Souther.
----------------------------------------------------------
----------------------------------------------------------
Dioxygen
Molecule made up of two covalently bonded oxygen atoms.
Souther.
----------------------------------------------------------
----------------------------------------------------------
GMP
Guanosine monophosphate. One of the four nucleotides
in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Donate-Molecular
The donation of energy or of a chemical entity by a
chemical object such as an atom or molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Double-Covalent-Bond
A chemical bond formed when two atoms share two pairs
of electrons. Alberts:ECB:45
----------------------------------------------------------
----------------------------------------------------------
Double-Covalent-CC-Bond
Double covalent bond between two carbons. Souther.
----------------------------------------------------------
----------------------------------------------------------
Double-Covalent-CN-Bond
Double covalent bond between carbon and nitrogen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Double-Covalent-CO-Bond
Double covalent bond between carbon and oxygen.
Souther.
----------------------------------------------------------
----------------------------------------------------------
E-Site
The site on the ribosome where the tRNA that has just
given up the growing polypeptide chain dissociates
from the ribosome. Alberts:ECB:230.
----------------------------------------------------------
----------------------------------------------------------
Electron-Acceptor
Atom or molecule that takes up electrons readily.
Upon gaining an electron, it is said to be reduced.
Alberts:ECB:G-7
----------------------------------------------------------
----------------------------------------------------------
Electron-Carrier
Molecule such as cytochrome C that transfers an
electron from a donor molecule to an acceptor
molecule. Alberts:ECB:G-7
----------------------------------------------------------
----------------------------------------------------------
Electron-Donor
Atom or molecule that gives up electrons readily.
In the process, it is said to become oxidized.
Alberts:ECB:G-7
----------------------------------------------------------
----------------------------------------------------------
Electron-Transfer
The transfer of electrons from one molecule to
another. Souther.
----------------------------------------------------------
----------------------------------------------------------
Electron
Fundamental subatomic particle with a unit negative
charge. Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
Endocytose
Uptake of material into a cell by an invagination of the
plasma membrane leading to internalization in a membrane-
bounded vesicle. Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
Endoplasmic-Reticulum
Labyrinthine, membrane-bounded compartment in the
cytoplasm of eucaryotic cells, where lipds are
secreted and membrane-bound proteins are made.
Alberts:ECB:G-7
----------------------------------------------------------
----------------------------------------------------------
Energy-Transfer
The transfer of energy from one entity to another.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Energy
The capacity to do work. RHCD:438.
----------------------------------------------------------
----------------------------------------------------------
Ensemble
A collection of distinct structures which function
together to carry out some task, as the respiratory
enzyme complex on mitochondrial membranes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Enzyme-Activation
To put into a state where it a can participate in an
action. Souther.
----------------------------------------------------------
----------------------------------------------------------
Enzyme
A protein that catalyzes a specific chemical reaction.
Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
Enzyme-Catalysis
A chemical reaction whose rate is
facilitated by the presence of an enzyme
which is not altered by the reaction.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Enzyme-Complex
A group of enzymes which act together to provide
structure or perform some function. Examples are
ATP synthesis and oxidative phosphorylation enzymes.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Essential-Amino-Acid
Amino acid that cannot be synthesized by humans (and
other vertebrates) and must be obtained from the diet.
Lehninger:PBC:G-5.
----------------------------------------------------------
----------------------------------------------------------
Ethanol-Group
Alcohol derived from ethane. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ethyl-Group
Hydrophobic chemical group derived from Ethane.
Alberts:ECB:G-11.
----------------------------------------------------------
----------------------------------------------------------
Eucaryote
Living organism composed of one or more cells with a
distinct nucleus and cytoplasm. Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-Cell
Cells which contain a nucleus and other organelles
in addition to cytoplasm. Modified from Alberts:ECB:9
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-Cytoplasm
The cytoplasm of eucaryotic cells containing the
nucleus and other organelles. Souther.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-DNA-Polymerase
Enzyme that catalyzes the synthesis or repair
of a DNA molecule from nucleoside triphosphate
precursors using a DNA template in eucaryotes.
Souther. see Alberts: ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-DNA-Strand
One of two strands that make up the DNA double helix.
The two strands run antiparallel and are held
together by hydrogen bonds between the bases.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-DNA-Transcription
Copying of one strand of DNA into a complementary RNA
sequence by the enzyme RNA Polymerase in eucaryotes. cf
Alberts:ECB:G-18
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-DNA
Double-stranded polynucleotide formed from two
separate chains of deoxyribonucleotide units;
serves as the carrier of genetic information in
eucaryotes. Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-Gene
Region of DNA that controls a discrete
hereditary characteristic, usually
corresponding to a single protein or RNA.
This definition includes the entire functional
unit, encompassing coding DNA sequences,
noncoding regulatory DNA sequences, and introns
Alberts:MBC:G-10.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-MRNA
RNA molecule that specifies the amino acid sequence of a
protein, produced by RNA splicing from
a larger RNA molecule made by RNA polymerase as a
complementary copy of DNA. It is translated into protein
in a process catalyzed by ribosomes. Alberts:ECB:G-11
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-Plasma-Membrane
Membrane that surrounds a eucaryotic cell.
Alberts:ECB:G-14
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-RNA-Transcript
The DNA transcription product in eucaryotes.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-RRNA
Eucaryotic rRNA molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-Ribosome
Ribosome found in cytoplasm of eucaryotes.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Eucaryotic-TRNA
Eucaryotic tRNA molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Exon
Segment of a eucaryotic gene that is transcribed into
RNA and codes for the amino acid sequence of part of a
protein. Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
Extracellular-Matrix
Complex network of polysaccharides (such as
glycosaminoglycans or cellulose) and proteins (such as
collagen) secreted by cells. A structural component
of tissues that also influences their development and
physiology. Alberts:ECB:G-7.
----------------------------------------------------------
----------------------------------------------------------
FADH2
Major electron carrier in metabolism; produced by
reduction of FAD during the oxidation of catabolites
such as succinate. Alberts:ECB:G-7
----------------------------------------------------------
----------------------------------------------------------
Fibrous-Protein
A protein with an elongated shape; typically one such
as collagen or intermediate filament protein that is
able to associate into long filamentous structures.
Alberts:ECB:G-8.
----------------------------------------------------------
----------------------------------------------------------
Formyl-Group
Chemical group consisting of a carbon atom linked
to an oxygen atom by a double bond.
Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Formylmethionine
Methionine modified with a formyl group attached to
the amino nitrogen. It is the amino acid which
initiates peptide chain formation in bacteria.
Souther. see Alberts:ECB:231
----------------------------------------------------------
----------------------------------------------------------
Free-Nucleotide
A nucleotide which is not part of DNA or RNA, and is
free in the medium. Souther.
----------------------------------------------------------
----------------------------------------------------------
Free-Ribosome
Ribosomes that are free in the cytoplasm. Souther.
----------------------------------------------------------
----------------------------------------------------------
Functional-MRNA-Transcript
The RNA transcript after all the post-transcription
processing has been completed, which includes RNA
capping, polyadenylation, and splicing. Souther.
----------------------------------------------------------
----------------------------------------------------------
Functional-RNA-Transcript
The RNA transcript after all the post-transcription
processing has been completed. (Compare with Primary
Transcript). Souther.
----------------------------------------------------------
----------------------------------------------------------
Functional-Vertebrate-MRNA-Transcript
The RNA transcript in vertebrates after all the
post-transcription processing has been completed.
Differs from lower organisms in that the RNA capping
involves methylating the ribose of the second
ribonucleotide as well. Souther.
----------------------------------------------------------
----------------------------------------------------------
GCCGCCAG-Like-Sequence
A DNA consensus sequence that forms part of the terminator
for DNA transcription. Alberts:ECB:217
----------------------------------------------------------
----------------------------------------------------------
UMP
Uridine monophosphate. One of the four nucleotides
in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
GTP
Major nucleoside triphosphate used in the synthesis of
RNA and in some energy-transfer reactions. Has a
special role in microtubule assembly, protein
synthesis, and cell signaling. Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Gene-Transcript
The RNA transcript of a single gene, which is the rule
for an mRNA transcript in eucaryotes. In procaryotes
the mRNA transcript may code for several genes.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Gene
Region of DNA that controls a discrete hereditary
characteristic of an organism, usually corresponding
to a single protein or RNA. Alberts:ECB:G8.
Genes generally include both transcription units and
flanking regulatory regions, but in operons they lack
flanking regions, ie, procaryotic genes include flanking
regulatory regions when alone, but not when part of an
operon. Souther.
----------------------------------------------------------
----------------------------------------------------------
Genome
The total genetic information carried by a cell or
an organism (or the DNA molecules that carry this
information. Alberts:ECB:G-8.
----------------------------------------------------------
----------------------------------------------------------
Globular-Protein
Any protein with an approximately rounded shape. Most
enzymes are globular. Alberts:ECB:G-8.
----------------------------------------------------------
----------------------------------------------------------
Glucose
A six-carbon sugar that plays a major role in the metabolism
of living cells. Stored in polymeric form as glycogen in
animal cells and as starch in plants. Alberts:ECB:G-8.
----------------------------------------------------------
----------------------------------------------------------
Glutamic-Acid
A polar amino acid with a propionic side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Glutamine
A polar amino acid with a propionic side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Glycine
A nonpolar amino acid. Glycine is the simplest amino
acid with hydrogen atom as the side chain. Souther
----------------------------------------------------------
----------------------------------------------------------
Glycolysis
The catabolic pathway by which a molecule of glucose
is broken down into 2 molecules of Pyruvic-Acid.
Lehninger:PBC:G-6.
----------------------------------------------------------
----------------------------------------------------------
Golgi-Apparatus
Membrane-bounded organelle in eucaryotic cells, where
the proteins and lipids made in the endoplasmic
reticulum are modified and sorted. Alberts:ECB:G-8.
----------------------------------------------------------
----------------------------------------------------------
Group
A collection of identical or functionally identical
molecules which act together to perform some functional
or structural role. Souther.
----------------------------------------------------------
----------------------------------------------------------
Guanine
A purine base which combines with a ribose base to form
guanosine. Guanosine phosphates are prominent
molecules in cells as GTP which participates in cell
signaling metabolism and nucleotides.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Guanosine
A nucleoside containing guanine and ribose that
when joined with a monophosphate forms one of the four
nucleotides in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Heterocyclic-Compound
A ring compound in which there are two or
more ring members. In organic compounds
the other atom is typically nitrogen or
oxygen. Souther.
----------------------------------------------------------
----------------------------------------------------------
Hexose
A six-carbon monosaccharide. Lodish:MCB:G-8.
----------------------------------------------------------
----------------------------------------------------------
High-Energy-Bond
Covalent bond whose hydrolysis releases an unusually
large amount of free energy under the conditions
existing in a cell. Examples include the
phosphodiester bonds in ATP and the thioester linkage
in acetyl CoA. Alberts:ECB:G-9
----------------------------------------------------------
----------------------------------------------------------
Histone-Complex
A group of basic proteins, rich in arginine and
lysine, that are associated with DNA in chromosomes.
Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Histone
One of a group of basic proteins, rich in arginine and
lysine, that are associated with DNA in chromosomes.
Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Hydrogen-Ion
A proton in aqueous solution - the basis of acidity.
Such protons readily combine with water molecules to
form H3O+, so that hydrogen ions in a strict sense are
a rarity. Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Hydrogen-Atom
A colorless, odorless, flammable element that combines
with oxygen to form water. The lightest of all
elements. RHCD:1st Revised:649.
----------------------------------------------------------
----------------------------------------------------------
Hydrogen-Bond
A weak chemical bond between an electronegative
atom such as nitrogen or oxygen and a hydrogen
atom bound to another electronegative atom.
Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Hydronium-Ion
The positive ion resulting from the addition of a
proton to a water molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Hydrophilic-Structure
Any chemical object which attracts water. Souther.
----------------------------------------------------------
----------------------------------------------------------
Hydrophobic-Structure
Any chemical object which repels water. Souther.
----------------------------------------------------------
----------------------------------------------------------
Hydroxyl-Group
Chemical group consisting of a hydrogen atom
linked to an oxygen, as in an alcohol.
Alberts:ECB:G-9.
----------------------------------------------------------
----------------------------------------------------------
Imidazole
An imino 5 membered ring. Souther.
----------------------------------------------------------
----------------------------------------------------------
Indole
An azole ring fused to a benzene ring. Souther.
----------------------------------------------------------
----------------------------------------------------------
Information-Sequence
A sequence which encodes information. Biological
examples are DNA, RNA, and the amino acid sequence of
proteins (which determines folding). Souther.
----------------------------------------------------------
----------------------------------------------------------
Inorganic-Molecule
Molecule lacking a carbohydrate skeleton. Souther.
----------------------------------------------------------
----------------------------------------------------------
Inorganic-Substance
Any chemical substance which does not
contain hydrocarbons.
----------------------------------------------------------
----------------------------------------------------------
Intermediate-Filament
Fibrous protein filament (10 nm in diameter) that
forms ropelike bundles in animal cells. Often
provides tensile strength to withstand tension applied
to the cell from outside. Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Internal-DNA-Sequence
A region of the DNA which is internal, thus having no free
5' or 3' end. Souther.
----------------------------------------------------------
----------------------------------------------------------
Internal-Membrane
Eucaryotic cell membrane other than the plasma
membrane. The membrane that surrounds an organelle
is an example. Alberts:ECB:G-10
----------------------------------------------------------
----------------------------------------------------------
Internal-RNA-Sequence
A region of the RNA which is internal, thus having no free
5' or 3' end. Souther.
----------------------------------------------------------
----------------------------------------------------------
Intron-Beginning-Sequence
The sequence that identifies the
5' splice site on an intron.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Intron-Branch-Sequence
The conserved sequence within an intron
containing an adenine which attacks and
breaks the bond between the last exon
nucleotide and the first (5') intron
nucleotide. Souther.
----------------------------------------------------------
----------------------------------------------------------
Intron-End-Sequence
The sequence that identifies the
3' splice site on an intron.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Intron
Region of a eucaryotic gene that does not code for
protein but is transcribed into an RNA molecule and then
excised by RNA splicing to produce mRNA.
Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Invertebrate-Organism
A multicellular organism lacking a vertebral cord.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Ion
Atom or molecule carrying an electrical charge, either
positive or negative. Alberts:ECB:G-10
----------------------------------------------------------
----------------------------------------------------------
Ionic-Bond
Attractive force that holds together two ions, one
positive and the other negative. Alberts:ECB:G-10
----------------------------------------------------------
----------------------------------------------------------
Isobutyl-Group
Hydrophobic chemical group derived from butane.
(CH3)2-CH2CH3. Souther.
----------------------------------------------------------
----------------------------------------------------------
Isoleucine
A nonpolar amino acid with a 1-methyl-isopropyl side
chain. Souther.
----------------------------------------------------------
----------------------------------------------------------
Isopropyl-Group
Hydrophobic chemical group derived from Isopropane.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Keto-Acid
Organic compounds containing the carboxy group
(-COOH) attached to a carbonyl group (C=O).
Souther.
----------------------------------------------------------
----------------------------------------------------------
Kinase
Enzyme that transfers a phosphate group from ATP (or
from another nucleoside triphosphate) onto another
molecule. Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Leucine
A nonpolar amino acid with a isobutyl side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Ligand
Molecule such as a hormone or a neurotransmitter that
that binds to a specific site on a protein.
Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Ligase
Enzyme that joins two segments of DNA or RNA together
end to end. Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Ligation
The joining of the 3' end of one nucleic acid strand with the
5' end of another, forming a continuous strand. see
Lodish:MCB:G-10. definition for ligase.
----------------------------------------------------------
----------------------------------------------------------
Lipase
Enzyme that catalyzes the cleavage of fatty acids from
from the glycerol moiety. Alberts:MBC:G-14.
----------------------------------------------------------
----------------------------------------------------------
Lipid-Bilayer
A bimolecular leaflet made up of lipid molecules,
forming the basic structure of the plasma membrane,
organelle membranes, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Lipid-Synthesis
The synthesis of lipids. Souther.
----------------------------------------------------------
----------------------------------------------------------
Lipid
Organic molecule, generally containing hydrocarbon
chains, that is insoluble in water but dissolves
readily in nonpolar organic solvents. One class,
phospholipids, forms the structural basis of
biological membranes. Alberts:ECB:G-10.
----------------------------------------------------------
----------------------------------------------------------
Lipolysis
The catabolic pathway by which lipids are hydrolyzed.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Living-Group
Any functionally related group of living entities,
like the cells of an organ, a population of
individuals, an ecological community, etc.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Lysine
A basic amino acid with a butylamine side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Lysosome
Intracellular membrane-bound organelle containing
digestive enzymes. The interior of a lysosome is
strongly acidic, and its enzymes are active at an acid
pH. Alberts:ECB:G-11.
----------------------------------------------------------
----------------------------------------------------------
MRNA
RNA molecule that specifies the amino acid sequence of a
protein. Produced by RNA splicing (in eucaryotes) from
a larger RNA molecule made by RNA polymerase as a
complementary copy of DNA. It is translated into protein
in a process catalyzed by ribosomes. Alberts:ECB:G-11
----------------------------------------------------------
----------------------------------------------------------
Macromolecule
Polymer molecule, such as a protein, nucleic
acid, or polysaccharide, with a molecular mass
greater than a few thousand daltons.
Alberts:ECB:G-11
----------------------------------------------------------
----------------------------------------------------------
Membrane
A thin, soft, pliable sheet or layer. Webster's 9th
NCD:741.
----------------------------------------------------------
----------------------------------------------------------
Metabolize
The sum of processes by which a particular
substance is handled by the body.
Webster's Ninth Collegiate Dictionary - under
Metabolism.
----------------------------------------------------------
----------------------------------------------------------
Methanol-Group
Alcohol derived from methane. Souther.
----------------------------------------------------------
----------------------------------------------------------
Methionine
A nonpolar amino acid with a methyl-thio-ethyl side
chain. Souther
----------------------------------------------------------
----------------------------------------------------------
Methyl-Group
Hydrophobic chemical group derived from methane.
Alberts:ECB:G-11.
----------------------------------------------------------
----------------------------------------------------------
Microtubule
Long, stiff, cylindrical intracellular structure, 20
nanometers in diameter, composed of the protein tubulin;
one of the major components of the cytoskeleton, used
by eucaryotic cells to regulate their shape and control
their movements. Alberts:ECB:G-11.
----------------------------------------------------------
----------------------------------------------------------
Mitochondrion
Membrane-bound organelle, about the size of a
bacterium, that carries out oxidative phosphorylation
and produces most of the ATP in eucaryotic cells.
Alberts:ECB:G-11.
----------------------------------------------------------
----------------------------------------------------------
Mitosis
Division of the nucleus of a eucaryotic cell, involving
condensation of the DNA into visible chromosomes.
Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Molecular-Complex
An assembly of molecules, usually macromolecules, held
together by noncovalent bonds and performing a specific
function, such as DNA replication or the synthesis of
phospholipids. Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Molecule
Group of atoms joined together by covalent bonds.
Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Monomer
Small molecule that can be linked to others of the same
type to form a larger molecule. Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Monophosphate
A compound containing a single phosphate group.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Monosaccharide
Any sijmple sugar with the formula (CH2O)n where n =
3-7. Alberts:MBC:G-16. Monosaccharides are the basic
unit of sugars and polysaccharides. Souther.
----------------------------------------------------------
----------------------------------------------------------
Multicellular-Organism
An organism composed of more than one cell.
Souther.
----------------------------------------------------------
----------------------------------------------------------
NAD-Plus
Molecule that participates in an oxidatin reaction by
accepting a hydride ion (H-) from a donor molecule
thereby producing NADH, which serves as an activated
carrier of electrons; important in the energy-producing
breakdown of sugars and fats. Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Nascent-Protein
A newly synthesized protein before any modifications.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Neutron
Fundamental subatomic particle found in the atomic
nucleus; it has a mass similar to that of a proton,
but no electric charge. Alberts:ECB:G-12.
----------------------------------------------------------
----------------------------------------------------------
Nitrogen-Atom
A colorless, odorless element constituting about 4/5ths
of the volume of the atmosphere and is present in
combined form in animal and vegetable tissues,
especially in proteins. RHCD:1st Revised:901.
----------------------------------------------------------
----------------------------------------------------------
Nitrogen-Molecule
Molecule made up of two or more nitrogen atoms.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Nitrogenous-Base
A base containing nitrogen.
----------------------------------------------------------
----------------------------------------------------------
Non-Transcribed-Region
Sequences of DNA which are not transcribed and do not
play any role in regulation. The so-described 'junk'
or 'spacer' DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Noncovalent-Bond
Chemical bond in which, in contrast to a covalent bond,
no electrons are shared. Noncovalent bonds are
relatively weak, but they can sum together to produce
strong, highly specific interactions between molecules.
Alberts:ECB:G-13
----------------------------------------------------------
----------------------------------------------------------
Nonessential-Amino-Acid
Amino acid that can be made by humans and other
vertebrates from simple precursors, and thus is not
required in the diet. Lehninger:PBC:G-9.
----------------------------------------------------------
----------------------------------------------------------
Nonpolar-Amino-Acid
Amino acids with side chains which are hydrophobic.
see Alberts:ECB:61.
----------------------------------------------------------
----------------------------------------------------------
Nonpolar-Molecule
Molecule that lacks any local accumulation of positive
or negative charge. Nonpolar molecules are generally
insoluble in water. Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nuclear-Envelope
Envelope surrounding the nucleus in a eucaryotic cell.
It consists of two lipid bilayer membranes - an outer
and an inner - and is perforated by nuclear pores.
Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nuclear-Pore
Channel through the nuclear envelope that allows
selected molecules to move between the nucleus and
cytoplasm. Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nuclease
Enzyme that cleaves nucleic acids. Matthews:BC:1157
----------------------------------------------------------
----------------------------------------------------------
Nucleic-Acid-Complex
A group of nucleic acids which act together to provide
structure or perform some function. They are often
held together by weak bonds such as hydrogen bonds.
Examples: DNA double helix and base pairs. Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleic-Acid-Degradation
The hydrolytic breakdown of nucleic acids.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleic-Acid-Molecule
RNA or DNA; consists of a chain of nucleotides joined
together by phosphodiester bonds. Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nucleic-Acid
Acid made up of chains of nucleotides. Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleolus
Structure in the nucleus where ribosomal RNA is
transcribed and ribosomal subunits are assembled.
Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nucleoplasm
The protoplasm of the nucleus. Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleoprotein-Complex
A complex made up of proteins and nucleic acids.
Examples include chromosomes, and the SNRP splicing
complex. Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleoprotein
Organic molecule containing both nucleic acid and
protein(s). Examples are ribosomes and SNRPs.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Nucleoside
Compound composed of a purine or pyrimidine base linked
to either a ribose or a deoxyribose sugar.
Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nucleotide-Sequence
A sequence of nucleotides which forms a nucleotide
polymer. Souther:2001
----------------------------------------------------------
----------------------------------------------------------
Nucleotide
Nucleoside with one or more phosphate groups joined
in ester linkages to the sugar part. DNA and RNA
are polymers of nucleotides. Alberts:ECB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Nucleus
The major organelle in eucaryotic cells, containing
DNA organized into chromosomes. Alberts:ECB:G-13
----------------------------------------------------------
----------------------------------------------------------
Operon
A set of contiguous prokaryotic structural genes that
are transcribed as a unit, along with the adjacent
regulatory elements that control their expression.
Matthews:Biochemistry:1158.
----------------------------------------------------------
----------------------------------------------------------
Organelle
A discrete structure or subcompartment of a eucaryotic
cell specialized to carry out a particular function;
especially a cellular substructure that is visible in
the light microscope. Examples include mitochondria
and the Golgi apparatus. (Alberts:ECB:G-13). Any
membrane bound structure found in the cytoplasm of
cells. Lodish:MCB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Organic-Acid
An organic molecule or substance which acts as an
acid (a hydrogen donor). Souther.
----------------------------------------------------------
----------------------------------------------------------
Organic-Compartment
A compartment within a living structure, surrounded
by a membrane. Examples are chambers of the heart,
and the nucleus of the cell.
----------------------------------------------------------
----------------------------------------------------------
Organic-Complex
A complex of several organic constituents, such as the
nucleolus or extracellular matrix, which serves some
structural or functional role. Souther:2001.
----------------------------------------------------------
----------------------------------------------------------
Organic-Layer
A layer made up of organic molecules, such as the
bimolecular layer that makes up the plasma membrane.
Souther:2001.
----------------------------------------------------------
----------------------------------------------------------
Organic-Molecule
Molecule containing hydrocarbon(s). Souther.
----------------------------------------------------------
----------------------------------------------------------
Organic-Structure
A structure made up of organic molecules, such as
the plasma membrane, organelles, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Organic-Substance
Any substance containing hydrocarbons. Souther.
----------------------------------------------------------
----------------------------------------------------------
Organism
Single or multicellular entities which are free living
and capable of reproduction. Souther.
----------------------------------------------------------
----------------------------------------------------------
Oxidase
Enzyme that catalyzes oxidation reactions in which
in which molecular oxygen serves as the electron
acceptor, but neither of the oxygen atoms is
incorporated into the product. Lehninger:PBC:G-9.
----------------------------------------------------------
----------------------------------------------------------
Oxidation
The loss of electrons from an atom or molecule as
occurs when hydrogen is removed from a molecule or
oxygen is added. Lodish:MCB:G-13
----------------------------------------------------------
----------------------------------------------------------
Oxidative-Phosphorylation
Process in bacteria and mitochondria in which ATP
formation is driven by the transfer of electrons
from food molecules to molecular oxygen. Involves
the intermediate generation of a pH gradient across
the membrane, which drives ATP synthesis by a
chemiosmotic coupling. Alberts:ECB:G-13p
----------------------------------------------------------
----------------------------------------------------------
Oxido-Reductase
General name for an enzyme that catalyzes reactions
in which one molecule is oxidized and the other is
reduced. Enzymes of this type are often called
oxidases, reductases, and dehydrogenases.
Alberts:ECB:168.
----------------------------------------------------------
----------------------------------------------------------
Oxido-Reduction-Reaction
The simultaneous loss of electrons from one molecule
(oxidation) and gain of by a second molecule of
electrons (reduction) by transfer from the first to
the second. Souther.
----------------------------------------------------------
----------------------------------------------------------
Oxygen-Atom
An element that is found free as a colorless tasteless
odorless gas in the atmosphere of whicdh it forms about
21 percent or combned in water, in most rocks and
minerals, and in numerous organic compounds, that is
capable of combining with all elements except the inert
gases, is active in physiological processes, and is
involved especially in comobustion processes.
Websters 9th NCD:843.
----------------------------------------------------------
----------------------------------------------------------
Oxygen-Molecule
Molecule made up of two or more oxygen atoms.
Souther.
----------------------------------------------------------
----------------------------------------------------------
P-Site
The site on the ribosome where the the tRNA holding the
growing polypeptide chain binds. Alberts:ECB:230.
----------------------------------------------------------
----------------------------------------------------------
Pantothenic-Acid
An organic acid that is one of the major parts of
coenzymeA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Particulate-Matter
Matter made up of particles. Souther.
----------------------------------------------------------
----------------------------------------------------------
Pentose
A five-carbon monosaccharide. The pentoses deoxyribose
and ribose are present in DNA and RNA respectively.
Lodish:MCB:G-13.
----------------------------------------------------------
----------------------------------------------------------
Peptide-Bond
Chemical bond between the carbonyl group of one amino
acid and the amino group of a second amino acid - a
special form of amide linkage. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Peroxidase
Enzyme that catalyzes the breakdown of peroxidase.
see Lehninger:PBC:G-10.
----------------------------------------------------------
----------------------------------------------------------
Peroxide
Molecule containing two covalently bonded oxygen
atoms. Souther.
----------------------------------------------------------
----------------------------------------------------------
Peroxisome
Small, membrane-bounded organelle that uses molecular
oxygen to oxidize organic molecules. Contains some
enzymes that produce hydrogen peroxide and others that
degrade hydrogen peroxide. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Phenol
A six-carbon ring alcohol with the carbons attached to
each other by conjugated double bonds and containing
one alcohol group. Souther.
----------------------------------------------------------
----------------------------------------------------------
Phenyl-Group
A six-carbon ring with the carbons attached to each
other by conjugated double bonds. Souther.
----------------------------------------------------------
----------------------------------------------------------
Phenylalanine
A nonpolar amino acid with a methyl side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Phosphatase
Enzyme that removes a phosphate group from a
molecule. see Alberts:ECB:G-15 for proteins.
----------------------------------------------------------
----------------------------------------------------------
Phosphate
A compound containing phosphate. In cells, they are
normally acidic.
----------------------------------------------------------
----------------------------------------------------------
Phosphoanhydride-Bond
A chemical bond formed between two phosphate groups.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Phosphodiester-Bond
A covalent chemical bond formed when two hydroxyl
groups are linked in ester linkage to the same
phosphate group, as in the case of adjacent nucleotides
in RNA or DNA. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Phosphorus-Atom
A solid, nonmetallic element that is a necessary
constituent for bones and nerves, and as a phosphate
forms high-energy bonds that provide the energy for
all biosynthetic reactions. Souther.
----------------------------------------------------------
----------------------------------------------------------
Phosphoryl-Group
A chemical group made up of 1 at least one phosphorus and
4 oxygens. Normally acidic in the cell. Souther.
----------------------------------------------------------
----------------------------------------------------------
Phosphorylation
The transfer of a phosphate to a molecule.
The bond formed is high energy and
permits the charged molecule to undergo reactions
that would otherwise be energetically unfavorable.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Plasma-Membrane
Membrane that surrounds a living cell.
Alberts:ECB:G-14
----------------------------------------------------------
----------------------------------------------------------
Polar-Amino-Acid
Amino acids with side chains which are hydrophilic.
see Alberts:ECB:61.
----------------------------------------------------------
----------------------------------------------------------
Polar-Molecule
A molecule in which the bonding electrons are attracted
more strongly to some atoms than to others, thereby
creating an uneven (or polarized) distribution of
electric charge. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Poly-A-Tail
The polyadenylate chain added to the end of a
newly synthesized mRNA in eucaryotes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Polydeoxyribonucleotide
A molecular chain of
deoxyribonucleotides chemically bonded
by a series of phosphodiester linkages.
Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Polymer
Large and usually linear molecule made by linking
together multiple identical or similar units
(monomers) in a repetitive fashion.
Alberts:ECB:G-14
----------------------------------------------------------
----------------------------------------------------------
Polymerase
General term for an enzyme that catalyzes addition of
subunits to a polymer. DNA polymerase, for example,
makes DNA, while RNA polymerase makes RNA.
Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Polymerize
To link together many identical or similar units
(monomers) in a repetitive fashion. Alberts:ECB:G-14;
derived from definition of polymer.
----------------------------------------------------------
----------------------------------------------------------
Polynucleotide
A molecular chain of nucleotides chemically bonded by a
series of phosphodiester linkages. Alberts:ECB:G-14.
Arbitrarily defined in this KB to be at least 50
nucleotides long, shorter nucleotide sequences are called
oligonucleotides. Note: the current lengths are
arbitrary. All source so far consulted just say a
'long' nucleotide sequence. Souther.
----------------------------------------------------------
----------------------------------------------------------
Pool
A collection of identical or functionally identical
molecules in a compartment of a cell.
----------------------------------------------------------
----------------------------------------------------------
Polypeptide
Linear polymer composed of multiple amino acids.
Proteins are large polypeptides. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Polyribonucleotide
A polymer of ribonucleotides. Example is RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Polyribosome
A mRNA-ribosome complex made up of several
ribosomes spaced along a mRNA. Alberts:ECB:232
----------------------------------------------------------
----------------------------------------------------------
Polysaccharide
Linear or branched polymer composed of sugars.
Examples are glycogen and cellulose.
Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Primary-RNA-Transcript
The newly transcribed RNA molecule before any
modifications have been made to it in the nucleus.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Primase
An RNA polymerase makes the short RNA primer needed
to initiate DNA chain elongation during DNA
replication. see Alberts:ECB:195.
----------------------------------------------------------
----------------------------------------------------------
Procaryote
Single-celled organism distinguished by the absence
of a distinct nucleus. modified Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Procaryotes
The taxonomic division consisting of single-celled
non-nucleated organisms (see Procaryote). Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-Cytoplasm
The cytoplasm of eucaryotic cells containing the
nucleus and other organelles. Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-DNA-Polymerase
Enzyme that catalyzes the synthesis or repair
of a DNA molecule from nucleoside triphosphate
precursors using a DNA template in procaryotes.
Souther. see Alberts: ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-DNA-Synthesis
A process by which a copy of all or part of a
procaryotic DNA molecule is made. Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-DNA
Double-stranded polynucleotide formed from two
separate chains of deoxyribonucleotide units;
serves as the carrier of genetic information in
procaryotes. Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-Gene
Region of procaryotic DNA that controls a
discrete hereditary characteristic, usually
corresponding to a single protein or RNA.
Most procaryotic genes are part of operons.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-MRNA
RNA molecule that specifies the amino acid sequence of a
protein. Made by RNA polymerase as a
complementary copy of DNA. It is translated into protein
in a process catalyzed by ribosomes. Alberts:ECB:G-11
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-RRNA
Procaryotic rRNA molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-Ribosomal-Protein
A protein that is part of the procaryotic ribosome.
There are 50 or more distinct proteins associated with
ribosomal RNA in the ribosome. Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-TRNA
Procaryotic tRNA molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Procaryotic-Ribosome
Ribosome found in cytoplasm of
procaryotes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Produce-Enzymatic
Any Enzymatic reaction process which requires
enzymes, including anabolic, catabolic, and transfer
reactions. Souther, 2001.
----------------------------------------------------------
----------------------------------------------------------
Proline
A nonpolar amino acid with a propyl side chain whose
distal end is attached to the amino group to form a
five-membered ring structure. Souther.
----------------------------------------------------------
----------------------------------------------------------
Promoter-Region
The region that encompasses the promoter, which is
usually in two separate sequences. Souther.
----------------------------------------------------------
----------------------------------------------------------
Promoter
Nucleotide sequence in DNA to which RNA polymerase
binds to begin transcription. Alberts:ECB:G-15.
----------------------------------------------------------
----------------------------------------------------------
Propionamino-Group
Amine derived from Propionamino acid.
CH2-CH2-CONH3 Souther.
----------------------------------------------------------
----------------------------------------------------------
Propionic-Group
Acidic chemical group derived from propane.
CH3-CH2-COO- Souther.
----------------------------------------------------------
----------------------------------------------------------
Propyl-Group
Hydrophobic chemical group derived from propane.
CH3-CH2-CH2- Souther.
----------------------------------------------------------
----------------------------------------------------------
Propylamine
Amine derived from propane. CH3-CH2-CH2-NH3.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Protease
Enzyme such as trypsin that degrades proteins by
hydrolyzing some of their peptide bonds.
Alberts:ECB:G-15.
----------------------------------------------------------
----------------------------------------------------------
Proteasome
Large protein complex in the cytosol that is
responsible for degrading cytosolic proteins that have
been marked for destruction by ubiquitination or by
some other means. Alberts:ECB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Protein-Chaperone
A protein which assists in the folding or the membrane
transport of another protein. Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Coat
The viral protein(s) which cover and protect
the viral nucleic acid.
----------------------------------------------------------
----------------------------------------------------------
Protein-Complex
A group of proteins which act together to provide
structure or perform some function. They are often
held together by weak bonds such as hydrogen bonds.
Examples: histones and the mitotic spindle. Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Domain
Compact and stably folded region of polypeptide.
Alberts:ECB:G-6.
----------------------------------------------------------
----------------------------------------------------------
Protein-Filament
A linear chain of protein molecules. As microtubules,
actin filaments, and intermediate filaments, they
constitute much of the cytoskeleton of all eucaryotic
cells and especially abundant in muscle cells.
see Alberts:ECB:16.
----------------------------------------------------------
----------------------------------------------------------
Protein-Initiator-Codon
The start codon for translation of mRNA into protein.
Sequence is AUG. Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Kinase
Enzyme that transfers a phosphate group from ATP to a
specific amino acid of a target protein. Cells contain
hundreds of different protein kinases, phosphorylating
different sets of target proteins. Alberts:ECB:G-15.
----------------------------------------------------------
----------------------------------------------------------
Protein
Linear polymer of amino acids linked together in a
specific sequence by peptide bonds. Alberts:ECB-G-15.
----------------------------------------------------------
----------------------------------------------------------
Protein-Phosphatase
Enzyme that removes a phosphate group by hydrolysis
from a protein, usually with high specificity.
Alberts:ECB:G-15.
----------------------------------------------------------
----------------------------------------------------------
Protein-Regulatory-Protein
A protein which regulates the activity of other
proteins, usually by directly attaching to them.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Sliding-Clamp
A protein which encircles the DNA strand and holds the
DNA polymerase in place during replication.
Alberts:ECB:197.
----------------------------------------------------------
----------------------------------------------------------
Protein-Stop-Codon
A codon in mRNA which signals the termination point for
translation of a polypeptide. Souther.
----------------------------------------------------------
----------------------------------------------------------
Proteolysis
The catabolic pathway by which lipids are hydrolyzed.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Proton
Positively charged subatomic particle found in atomic
nuclei. Also exists as an independent chemical species
as a positive hydrogen ion (H+). Alberts:ECB:G-15.
----------------------------------------------------------
----------------------------------------------------------
Protoplasm
The organized colloidal complex of organic and
inorganic substances that constitutes the living
cell or organelle. WNCD:947.
----------------------------------------------------------
----------------------------------------------------------
Purine
A nitrogenous compound containing two fused
heterocyclic rings. Two purines, adenine and guanine,
commonly are found in DNA and RNA. Lodish:MCB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Pyrimidine
A nitrogenous compound containing one heterocyclic
ring. Two pyrimidines, cytosine and thymine, are
commonly found in DNA. Lodish:MCB:G-14.
----------------------------------------------------------
----------------------------------------------------------
Pyruvic-Acid
An intermediate compound in the metabolism of
carbohydrates, proteins, and fats.
PubMed:MeSH:From Stedman, 26th ed.
Formula: CH3COCOOH. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-3prime-UTR
The sequence at the end of the mRNA which
is not translated. In eucaryotes, it is
partly trimmed and a poly-A tail is
added. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-5prime-UTR
The sequence at the beginning of the mRNA which
is not translated. In eucaryotes, it is partly
trimmed and a poly-A tail is added. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Anticodon
Sequence of three nucleotides in a transfer RNA
molecule that is complementary to the three
nucleotide codon on a messenger RNA molecule; the
anti-codon is matched to a specific amino acid
covalently attached to the transfer RNA molecule.
Alberts:ECB:G-2.
----------------------------------------------------------
----------------------------------------------------------
RNA-Coding-Sequence
A region of the RNA which codes for all or part of a
protein. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Codon
Sequence of three nucleotides in a RNA molecule that
represents the instruction for incorporation of a
specific amino acid into a polypeptide chain.
cf Alberts:ECB:G-5 (codon).
----------------------------------------------------------
----------------------------------------------------------
RNA-Molecule
Polymer formed from covalently linked ribonucleotide units.
Alberts:ECB:G-16
----------------------------------------------------------
----------------------------------------------------------
RNA-Noncoding-Sequence
The part of messenger RNA which is not translated.
Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Polymerase
Enzyme that catalyzes the synthesis of an RNA
molecule on a DNA template from nucleoside
triphosphate precursors (Alberts: ECB:G-16).
----------------------------------------------------------
----------------------------------------------------------
RNA-Regulatory-Protein
A protein which regulates mRNA processing or
translation. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Regulatory-Sequence
A sequence of mRNA ribonucleotides on an RNA transcript
that regulates the processing of RNA or translation
of RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Sequence
A nucleotide sequence of ribonucleotides.
Souther.
----------------------------------------------------------
----------------------------------------------------------
RNA-Transcript
RNA product of DNA transcription (Alberts:MBC:1994).
----------------------------------------------------------
----------------------------------------------------------
RNA
Acid consisting of a chain of ribonucleotides. Souther.
----------------------------------------------------------
----------------------------------------------------------
RRNA
Any one of a number of specific RNA molecules that form
part of the structure of a ribosome and participate in
the synthesis of proteins. Alberts:ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Reduction
The gain of electrons by an atom or molecule as
occurs when hydrogen is added from a molecule or
oxygen is removed. Lodish:MCB:G-15
----------------------------------------------------------
----------------------------------------------------------
Regulatory-Protein
A protein whose role is to affect the activity of DNA,
RNA, or proteins or other cell constituents.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Regulatory-Region
A region or site on DNA, RNA, or a Protein which regulates
the processing or activity of the molecule. Souther
----------------------------------------------------------
----------------------------------------------------------
Regulatory-Sequence
A sequence of nucleotides that regulates the
the synthesis of DNA, RNA, or protein. Souther.
----------------------------------------------------------
----------------------------------------------------------
Regulatory-Site
A site on a molecule to which a regulatory ligand
binds and alters the activity or function of that
molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Removal-Enzyme
Enzyme that removes a group from a molecule. Examples
are phosphatases and deaminases. Souther.
----------------------------------------------------------
----------------------------------------------------------
Remove-Enzymatic
The enzymatic removal of a group from an atom or
molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Replace-Biological
The substitution or replacement of one
molecule or chemical group by another.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Replace-Enzymatic
The substitution or replacement of one
molecule or chemical group by another.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Replication-Fork
The site on the DNA molecule of DNA replication.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Replication-Origin-Sequence
A DNA sequence that attracts initiator proteins
for DNA translation. Alberts:ECB:190
----------------------------------------------------------
----------------------------------------------------------
Replication-Origin
Site on a chromosome at which DNA replication begins.
Alberts:ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Sugar-Phosphate
A deoxyribose sugar phosphate. Souther
----------------------------------------------------------
----------------------------------------------------------
Ribonuclease
Enzyme that cleaves RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribonucleic-Acid-Degradation
The hydrolytic breakdown of Ribonucleic acids.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribonucleoprotein
A nucleoprotein that makes up part of a
ribosome. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribonucleotide
Nucleotide containing D-ribose as the pentose
component. Lehninger:PBC:G-12.
----------------------------------------------------------
----------------------------------------------------------
Ribose
A Ribose which forms the carbohydrate moiety of
nucleotides, both when free and when incorporated
into RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribosomal-Peptidyl-Transferase
The enyzme that catalyzes the transfer of the growing
polypeptide chain to the amino acid on the newly docked
tRNA during protein synthesis. The enzyme is part of
the ribosomal nuceloprotein complex. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribosomal-Protein
A protein that is part of the ribosome. There are 50
or more distinct proteins associated with ribosomal
RNA in the ribosome. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribosome
Particle composed of ribosomal RNAs and ribosomal
proteins that associates with messenger RNA and
catalyzes the synthesis of protein. Alberts:ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Ribosome-Binding-Site
A binding site on the ribosome that
contains a nucleotide sequence which
matches a complementary sequence on
tRNA or mRNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ribosome-Release-Factor
A protein which participates in the release of the
ribosome from the mRNA at the end of translation.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Ring-Compound
Compound in which some or all of its member atoms are
joined in a ring.
----------------------------------------------------------
----------------------------------------------------------
Rough-Endoplasmic-Reticulum
Region of the endoplasmic reticulum associated with
ribosomes; involved in the synthesis of secreted and
membrane-bound proteins. Alberts:ECB:G-16.
----------------------------------------------------------
----------------------------------------------------------
Secreted-Protein
A protein that is secreted from the cell. Souther.
----------------------------------------------------------
----------------------------------------------------------
Series
A collection of identical or functionally identical
molecules which repeat in a linear manner along some
structure. Examples: protein filaments made up of
molecules attached end to end, the series of hydrogen
bonds in DNA, etc. Souther.
----------------------------------------------------------
----------------------------------------------------------
Serine
An uncharged polar amino acid with a methanol side
chain. Souther
----------------------------------------------------------
----------------------------------------------------------
Sigma-Factor
A subunit of procaryotic RNA polymerase which interacts
with the promoter to signal the polymerase to initiate
transcription at a specific sequence in template DNA.
Lodish:MCB:347.
----------------------------------------------------------
----------------------------------------------------------
Single-Strand-Binding-Protein
A protein which binds to single-stranded DNA during DNA
replication to prevent it from reforming the double
helix Alberts:ECB:197.
----------------------------------------------------------
----------------------------------------------------------
Smooth-Endoplasmic-Reticulum
Region of the endoplasmic reticulum not associated with
ribosomes; involved in synthesis of lipids.
Alberts:ECB:G-17.
----------------------------------------------------------
----------------------------------------------------------
SnRNP-Ensemble
A complex of nucleoprotein enzymes involved in the
splicing of mRNA. Alberts:ECB:220
----------------------------------------------------------
----------------------------------------------------------
SnRNP
A nucleoprotein enzyme involved in the splicing of
mRNA. Alberts:ECB:220
----------------------------------------------------------
----------------------------------------------------------
Spacer-DNA-Region
The DNA region between Genes which is not transcribed.
Can be up to 100,000 nucleotides long.
Alberts:ECB:218.
----------------------------------------------------------
----------------------------------------------------------
Structural-Protein
A protein that provides structure to the cell, such
as the proteins forming the cytoskeleton or the
nuclear lamina. Souther
----------------------------------------------------------
----------------------------------------------------------
Sub-Organismal-Entity
Suborganismal 'living' components of organisms,
including systems, organs, tissues, and cells.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Subatomic-Particle
A particle that is one of the constituents of an atom.
Souther.
----------------------------------------------------------
----------------------------------------------------------
TMP
Thymidine monophosphate. One of the four nucleotides
in DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Subcellular-Compartment
A compartment within the cell, surrounded by a
membrane. Examples are mitochondrial matrix,
the nucleoplasm, and the compartment within the
endoplasmic reticulum.
----------------------------------------------------------
----------------------------------------------------------
Substrate
The molecule on which an enzyme acts.
Alberts:ECB:G-17.
----------------------------------------------------------
----------------------------------------------------------
Sulfur-Atom
A nonmetallic element that occurs either free or
combined especially in sulfides and sulfates, and is a
constituent of proteins. Websters 9th NCD:1180.
----------------------------------------------------------
----------------------------------------------------------
Synthase
An enzyme involved in the synthesis of large molecules
from smaller which requires the input of energy.
Souther (see Alberts:ECB:G-2 on anabolic).
----------------------------------------------------------
----------------------------------------------------------
TATA-Box
A DNA consensus sequence that forms part of the promoter
for DNA transcription. Alberts:ECB:217
----------------------------------------------------------
----------------------------------------------------------
TRNA-Charging
The attachment of an amino acid to the appropriate tRNA
during RNA translation. Souther.
----------------------------------------------------------
----------------------------------------------------------
TRNA
Small RNA molecule used in protein synthesis as an
adaptor between a specific codon in mRNA, and specific
amino acids. Each type of tRNA molecule is covalently
linked to a particular amino acid and recognizes a
particular codon or set of codons by base-pairing.
Alberts:ECB:G-18.
----------------------------------------------------------
----------------------------------------------------------
TTGACA-Like-Sequence
A DNA consensus sequence that forms part of the promoter
for DNA transcription. Alberts:ECB:217.
----------------------------------------------------------
----------------------------------------------------------
TTP
Nucleoside triphosphate used in the synthesis of
DNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
TTTT-Like-Sequence
A DNA consensus sequence that forms part of the
terminator for DNA transcription. Alberts:ECB:217.
----------------------------------------------------------
----------------------------------------------------------
Terminator-Region
The region which contains the terminator
sequences.
----------------------------------------------------------
----------------------------------------------------------
Terminator
A DNA sequence that appears at the end of a
transcriptional unit and signals the end of transcription.
Lehninger:PBC:G-13.
----------------------------------------------------------
----------------------------------------------------------
Thioester-Bond
High-energy bond formed by a condensation reaction
between an acid (acyl) group and a thiol group (-SH);
seen, for example, in acetyl CoA and in many enzyme-
substrate complexes. Alberts:ECB:G-17.
----------------------------------------------------------
----------------------------------------------------------
Thiol-Group
Chemical group containing sulfer and hydrogen
found in the amino acid cysteine and other
molecules. Two sulfhydryls can join to produce a
disulfide bond. Alberts:ECB:G-17
----------------------------------------------------------
----------------------------------------------------------
Threonine
An uncharged polar amino acid with an ethanol side
chain. Souther
----------------------------------------------------------
----------------------------------------------------------
Thymidine
A nucleoside containing thymine and ribose.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Thymine
A pyrimidine base which combines with a ribose base to
form thymidine. Thymidine triphosphates are one of the
building block monomers for DNA.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Toluene
Methylbenzene. Souther
----------------------------------------------------------
----------------------------------------------------------
Transcription-Unit
A stretch of DNA that is naturally transcribed in a
single operation to produce a single primary transcript.
Can be (the coding part of) an operon or a gene.
Strachan:HMG:556. Includes untranslated regions as
well as the cistron. Souther
----------------------------------------------------------
----------------------------------------------------------
Transfer-Enzymatic
The transfer of a group from one molecule to another,
such as a phosphate, amino group, etc, facilitated by
enzyme(s). Souther.
----------------------------------------------------------
----------------------------------------------------------
Transfer-Enzyme
A protein that catalyzes the transfer of a group from
one molecule to another, e.g. oxido-reductases.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Translation-Initiation-Factor
A protein involved in the initiation of translation of
mRNA into protein. Souther.
----------------------------------------------------------
----------------------------------------------------------
Triphosphate
A compound containing a three phosphate groups in a
chain. Souther.
----------------------------------------------------------
----------------------------------------------------------
Tryptophan
A nonpolar amino acid with an indole side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Tubulin-Molecule
A globular protein that polymerizes into microtubules.
Alberts:ECB:G-18.
----------------------------------------------------------
----------------------------------------------------------
Tyrosine
An uncharged polar amino acid with a phenol side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
UAG
A codon in mRNA which signals the termination point for
translation of a polypeptide. Souther.
----------------------------------------------------------
----------------------------------------------------------
UGA
A codon in mRNA which signals the termination point for
translation of a polypeptide. Souther.
----------------------------------------------------------
----------------------------------------------------------
UTP
Nucleoside triphosphate used in the synthesis of
RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
UUA
A codon in mRNA which signals the termination point for
translation of a polypeptide. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ubiquinated-Protein
Protein which has been tagged with ubiquitin, which
marks it for degradation by proteasomes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ubiquitin-Binding-Enzyme
Specialized enzyme that tags a protein to be degraded
with Ubiquitin. Souther.
----------------------------------------------------------
----------------------------------------------------------
Ubiquitin
A protein which attaches to other proteins and marks
them for degradation by proteasomes. Souther.
----------------------------------------------------------
----------------------------------------------------------
Uncharged-Polar-Amino-Acid
A polar amino acid with neutral charge. Souther.
----------------------------------------------------------
----------------------------------------------------------
Unicellular-Organism
An organism consisting of a single cell. Souther.
----------------------------------------------------------
----------------------------------------------------------
Uracil
A pyrimidine base which combines with a ribose base to
form uridine. Uridine triphosphates are one of the
building block monomers for RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Uridine
A nucleoside containing uridine that when joined
with a monophosphate group forms one of the four
nucleotides in RNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Valine
A nonpolar amino acid with a propyl side chain.
Souther
----------------------------------------------------------
----------------------------------------------------------
Vesicle
Small, membrane-bounded, spherical organelle in the
cytoplasm of a eucaryotic cell. Alberts:ECB:G-18.
----------------------------------------------------------
----------------------------------------------------------
Viral-DNA
The DNA of a virus. Souther.
----------------------------------------------------------
----------------------------------------------------------
Viral-Nucleic-Acid
The hereditary material of a virus, either DNA or RNA.
----------------------------------------------------------
----------------------------------------------------------
Virus
Infectious particle consisting of nucleic acid (RNA or
DNA) enclosed in a protein coat; replicates by
parasitizing the reproductive machinery of a host
cell, from which new virus particles ar released to
infect other cells. Often the cause of disease.
(Alberts:ECB:G-18.)
----------------------------------------------------------
----------------------------------------------------------
Water-Molecule
Molecule made up of two hydrogen atoms each covalently
bonded to the same oxygen atom. Souther.
----------------------------------------------------------
----------------------------------------------------------
Water
Water as a substance. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Acid
Acid consisting of a chain of deoxyribonucleotides.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Binding-Site
Region on the surface of a protein - typically a
cavity or groove - that is complementary in shape to
another molecule (the ligand) and therefore can bind it
through the formation of multiple weak (noncovalent)
bonds. Alberts:ECB:G-3.
----------------------------------------------------------
----------------------------------------------------------
Chemical-Information-Sequence
A sequence which encodes information. Biological
examples are DNA, RNA, and the amino acid sequence of
proteins (which determines folding). Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-3prime-UTR
The sequence at the end of the transcription
unit which is not translated. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-5prime-UTR
The sequence at the beginning of the
transcription unit which is not later translated
Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Strand-Fragment
A part of a DNA strand with free ends. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Substance
DNA as the substance which makes up the hereditary
material of the cell. Souther.
----------------------------------------------------------
----------------------------------------------------------
Free-Nucleotide-Sequence
A nucleotide sequence with a free 5'-triphosphate and
free 3'-OH, i.e. a sequence which is not an internal
sequence. Examples include DNA-Strand, Free-Nucleotide.
Souther.
----------------------------------------------------------
----------------------------------------------------------
GCA-Codon
A codon in mRNA which signals the termination point for
translation of a polypeptide. Souther.
----------------------------------------------------------
----------------------------------------------------------
Gene-Expression
The process by which a gene exerts its effect on a
cell or an organism, usually by directing the
synthesis of an RNA molecule that can be translated
into a protein with a characteristic activity.
Alberts:ECB:G-8. The product of gene expression may
also be rRNA or tRNA. Souther.
----------------------------------------------------------
----------------------------------------------------------
Information-Transfer
The transfer of information from one entity to
another. Souther.
----------------------------------------------------------
----------------------------------------------------------
Internal-Nucleotide-Sequence
A region of a nucleotide sequence which
is internal, thus having no free 5' or
3' end. Souther.
----------------------------------------------------------
----------------------------------------------------------
Protein-Synthesis
The commonest form of gene expression in which
proteins are synthesized as directed by a gene via
the intermediary of RNA which is translated into
protein. Souther.
----------------------------------------------------------
----------------------------------------------------------
Replication-Machine
The multiprotein complex that promotes DNA synthesis
at the replication fork. Lehninger:PBC:G-12.
----------------------------------------------------------
----------------------------------------------------------
A-T-Base-Pair
The nucleotide base pair resulting from the hydrogen
bonding of adenine and thymine in DNA molecules.
Souther.
----------------------------------------------------------
----------------------------------------------------------
A-U-Base-Pair
The base pair resulting from the hydrogen bonding of
adenine and uracil in RNA molecules. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Chain-Elongation
The process of adding deoxyribonucleotides to
the end of a growing DNA sequence during
DNA replication or repair. Souther
----------------------------------------------------------
----------------------------------------------------------
DNA-Lagging-Strand-Synthesis
The synthesis of a daughter strand using the
lagging strand as the template. The lagging
strand runs 5' to 3' so the daughter strand is
synthesized 3' to 5', therefore discontinuously.
The resulting 'Okazaki fragments' must be
stitched together by a DNA ligase. Souther.
----------------------------------------------------------
----------------------------------------------------------
DNA-Molecule-Segment
A segment of a DNA molecule. Souther.
----------------------------------------------------------
----------------------------------------------------------
Deoxyribose-Monophosphate
A deoxyribose sugar phosphate. Souther
----------------------------------------------------------
----------------------------------------------------------
Dinucleotide
A sequence of two nucleotides. Larger sequences
(3-50) are termed oligonucleotides. Souther
----------------------------------------------------------
----------------------------------------------------------
G-C-Base-Pair
The base pair resulting from the hydrogen bonding of
Guanine and Cytosine in RNA molecules. Souther.
----------------------------------------------------------
----------------------------------------------------------
Genetic-Information-Sequence
A genetic sequence which encodes information.
Souther.
----------------------------------------------------------
----------------------------------------------------------
Okazaki-Fragment
A short length of DNA produced on the lagging strand
during DNA replication, discovered by R. Okazaki. They
are rapidly joined by DNA ligase to form a continuous
DNA strand. Alberts:MBC:G-17.
----------------------------------------------------------
----------------------------------------------------------
Oligonucleotide
A molecular chain of nucleotides chemically bonded by a
series of phosphodiester linkages. Alberts:ECB:G-14.
Arbitrarily defined in this KB to be between 3 and 49
nucleotides long, shorter nucleotide sequences are called
oligonucleotides. Note: the current lengths are
arbitrary. All source so far consulted just say a
'short' nucleotide sequence. Souther.
----------------------------------------------------------
----------------------------------------------------------
Replicon-Replication
A process by which a copy of a replicon within
a Replicon molecule is made. Souther. see
Mathews:BC:1160
----------------------------------------------------------
----------------------------------------------------------
Replicon
A unit in the genome that consists of an origin of
replication and all the DNA that is replicated from
that origin. Mathews:BC:1160
----------------------------------------------------------