Keywords 2 Flashcards
Polycistronic mRNA
Prokaryotes: contains codons of more than one cistron and codes for more than one protein
Constitutive
A gene that is transcribed at a relatively constant level
Inducible
To cause an increase in the transcription of the RNA of a gene
Catabolite repression
Allows micro-organisms to adapt quickly to a preferred carbon and energy source first
Consensus sequences
The calculated order of most frequent residues found at each position in a sequence alignment
Structural gene
Codes for any RNA or protein product other than a regulatory factor
Regulatory gene
A gene involved in controlling the expression of one or more other genes
Core promoter
A region of DNA that initiates transcription of a particular gene
General (basal) transcription factor (GTFs)
Bind to specific sites (promoter) on DNA to activate transcription of genetic information from DNA to messenger RNA
Transcriptional activator (repressor protein)
A protein that increases gene transcription of a gene or set of genes
Transcription factor (sequence specific)
A transcription factor is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence
Enhancer
A short (50–1500 bp) region of DNA that can be bound by protein activators to increase the likelihood that transcription of a particular gene will occur
DNA binding domain
An independently folded protein domain that contains at least one structural motif that recognises double- or single-stranded DNA
Dimerisation domain
A macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound
Activation domain
Similar to transcription factor
Cooperativity
An interaction between molecules that results in a stable physical association between those molecules
Epigenetics
Study of heritable phenotype changes that do not involve alterations in the DNA sequence
5-methylcytosine
A methylated form of the DNA base cytosine that may be involved in the regulation of gene transcription
DNA methyltransferase
Family of enzymes that catalyse the transfer of a methyl group to DNA
CpG islands
Regions with a high frequency of CpG sites
Chromatin modification
The dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression
Chromatin remodelling
The dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression
Nucleosome
A basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein cores
Histone code
The transcription of genetic information encoded in DNA is in part regulated by chemical modifications to histone proteins
Histone acetylase
Enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl-CoA
Histone deacetylase
Class of enzymes that remove acetyl groups from an ε-N-acetyl lysine amino acid on a histone
Euchromatin
A lightly packed form of chromatin that is enriched in genes, and is often under active transcription
Heterochromatin
A tightly packed form of DNA or condensed DNA, which comes in multiple varieties
Insulators/boundary elements
A type of cis-regulatory element known as a long-range regulatory element
Genomic imprinting
An epigenetic phenomenon that causes genes to be expressed in a parent-of-origin-specific manner
Translation
The process in which ribosomes synthesise proteins after the process of transcription
Ribosome
Complex molecular machine that serves as the site of biological protein synthesis
Amino acid
Organic compounds containing amine and carboxyl functional groups, along with a side chain specific to each amino acid
Genetic code
Set of rules used by living cells to translate information encoded within genetic material into proteins
Redundancy
Situations where a given biochemical function is redundantly encoded by two or more genes
mRNA
Convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression
tRNA
An adaptor molecule composed of RNA that serves as the physical link between the mRNA and the amino acid sequence of proteins
rRNA
RNA component of the ribosome, and is essential for protein synthesis in all living organisms
Codon
Unit that consists of 3 adjacent bases on a DNA molecule that determines the position of a specific amino acid in a protein molecule during protein synthesis
Anticodon
Triplet of nucleotides in transfer RNA that is complementary to the codon in messenger RNA that specifies the amino acid
Charged (aminoacyl)-tRNA
tRNA to which its cognated amino acid is chemically bonded (charged)
Aminoacyl-tRNA synthetase (tRNA ligase)
An enzyme that attaches the appropriate amino acid onto its tRNA
‘Wobble base’
Pairing between two nucleotides in RNA molecules that does not follow base pair rules.
Ribozyme
RNA molecules that are capable of catalysing specific biochemical reactions, similar to the action of protein enzymes
Start codon
First codon of an mRNA transcript translated by a ribosome
Stop codon
Nucleotide triplet within mRNA that signals a termination of translation into proteins
A-site
First binding site in the ribosome
