Chapter 18

39 cards

Regulation of Gene Expression

Created Oct 23, 2010
by eevron

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	Side A	Side B
1	-cells can adjust the activity of enzymes already present-typical of anabolic pathways-allow...	feedback inhibition
2	-cells can adjust the production level of certain enzymes; regulate the expression of genes...	Cell's regulation of production level of enzymes/ Operon Model
3	-5 genes that code for the subunits of these enzymes are clustered together on bacterial chromosome -a...	E.coli Transcription Unit
4	-all the enzymes for the metabolic pathway are synthesized at one time -segment of DNA -positioned...	operator
5	-the operator, the promoter, and the genes they control -entire stretch of DNA required...	Operon
6	-operon can be switched off by this -binds to the operator and blocks attachment of RNA...	repressor
7	-repressor is the product of this (called trpR in E. trp operon)-located some distance from...	regulatory gene
8	-tryptophan is this in the trp operon-small molecule that cooperates with a repressor protein...	Corepressor
9	-transcription is usually on but can be inhibited when specific molecule binds allosterically...	Repressible operon
10	-usually off but can be stimulated when a specific molecule interacts with a regulatory protein...	inducible operon
11	-specific small molecule that inactivates the repressor-lac operon is always active and needs...	Inducer
12	-the allosteric regulatory protein interacts with this small, organic molecule, which accumulates...	cyclic AMP (cAMP)
13	-the regulatory protein -is an activator, protein that binds to DNA and stimulates transcription...	Catabolite activator protein (CAP)
14	-under dual control: negative control by the lac repressor, positive control by CAP-state...	lac operon: control
15	-human cell prob expresses 20% of its genes at a time-almost all cells of an organisms contain...	Differential gene expression
16	-often equated with transcription for bacteria and eukaryotes -signal-->chromatin-->chromatin...	Gene expression
17	-basic unit is nucleosome -compact form -location of gene's promoter relative to...	Regulation of chromatin Structure
18	-acetyl groups are attached to lysines in histone tails -when lysines are acetylated,...	histone acetylation
19	-addition of methyl groups--promotes condensation of chromatin	methylation
20	-addition of phosphate group to an amino acid next to a methylated amino acid can have the...	phosphorylation
21	-many modifications to histone tails can affect chromatin structure and gene expression -specific...	histone code hypothesis
22	-methylation pattern maintained accounts for this in mammals-methylation permanently regulates...	genomic imprinting
23	-chromatin modifications that do not entail a change in the DNA sequence, but may be passed...	Epigenetic inheritance
24	-cluster of proteins that assembles on the promoter sequence at the upstream end of the gene-one...	Transcription initiation complex
25	-segments on noncoding DNA that help regulate transcription by binding certain proteins -these...	control elements
26	-RNA polymerase needs assistance of these proteins -some essential to transcription of...	Transcription factors
27	-high levels of transcription at appropriate time and place depend on interaction of control...	specific transcription factors
28	-located close to the promoter	proximal control elements
29	-more distant -enhancers--may be thousands of nucleotides upstream or downstream of a...	distal control elements
30	-protein-mediating bending of DNA is thought to bring bound activators in contact with these,...	mediator proteins
31	-DNA binding domain, part of proteins 3D structure that binds to DNA-one or more activation...	structure of activator proteins
32	-some repressors recruit proteins that deacetylate histones, leading to reduced transcription -most...	silencing
33	-operons like in bacteria have not been found in eukaryotes-co-expressed genes that are clustered...	coordinately controlled genes-eukaryotes
34	-transcription alone does not constitute gene expression -these mechanisms allow cell...	Post-transcriptional regulation
35	-regulation at RNA-processing level-different mRNA molecules are produced from the same primary...	Alternative RNA splicing
36	-bacterial mRNA molecules degraded by enzymes within a few minutes of synthesis -short...	mRNA degradation
37	-common pathway of mRNA breakdown begins with enzymatic shortening of poly-A tail -helps...	mRNA breakdown
38	-translation presents another opportunity for regulation: initiation -initiation...	Initiation of translation
39	-translation of all mRNAs in a cell may be regulated simultaneously -activation or inactivation...	global control