Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
Constitutive Genes
|
Genes that are always active
|
|
|
Regulated Genes
|
In Eukaryotes, encode enzymes for metabolic processes that are not constantly required. Produced when needed
|
|
|
Metabolic Pathway (Cluster)
|
Prokarotes only . . . NOT SURE!!
|
|
|
Substrate Induction
|
Turning on of enzyme synthesis in the presence of some "raw material"
|
|
|
Inducible Enzyme
|
Enyme whose synthesis is regulated by substrate induction
|
|
|
End-product regression
|
reduction in the expression of the enzyme-encoding due to some sort of negative feedback
|
|
|
Repression
|
Reduction in expression of any regulated gene
|
|
|
Effectors
|
Control enzyme synthesis by either repressing or inducing
|
|
|
Operon
|
A group of genes belonging to a single regulatory sub-unit, with related functions, that are clustered together with DNA sequences that allow the genes to be turned on/off simultaneously
|
|
|
Repressor Protein
|
A regulatory gene product that inhibits expression of other genes
|
|
|
Operator
|
A nucleotide sequence that overlaps the the promoter. Repressor is able to bind to it.
|
|
|
Polycistronic mRNA
|
mRNA molecules which code for more than one polypeptide
|
|
|
Binding of the _____ to the ______ keeps the operon's genes turned off
|
Binding of the _repressor_ to the _operator_ keeps the operon's genes turned off
|
|
|
Structural Gene
|
Gene that codes for a protein
|
|
|
Regulatory Gene
|
Binds to Operator, blocking Translation. Constitutive protein
|
|
|
The lac repressor
|
A gene regulatory protein
A DNA binding protein - binds to the operator, blocking the promoter so RNA Polymerase cannot bind |
|
|
When lactose binds to ________ its conformation changes so that it can no longer bind to the _________
|
When lactose binds to _respressor_ its conformation changes so that it can no longer bind to the _operator_
|
|
|
Control of gene expression can be found at 5 levels:
|
- Genomic
- Transcription - RNA Processing (splicing, capping, alterbative splicing & Nuclear export) - Translation (translation speed & breakdown of RNA) - Controlling protein activity (and breakdown), e.g. folding, cleavage, import to organelle |
|
|
Clustering
|
Prokaryotes only! In Eukaryotes each gene is regulated independently
|
|
|
Specialized cells arise from ________
|
Specialized cells arise from _differential gene expression_
|
|
|
DNA microarrays show expression of large numbers of genes in different tissues by . . .
|
. . . isolating mRNA from cells, showing which genes are turned on
|
|
|
Proximal Control Elements
|
Sequences between 100-200 BPs upstream of the code promoter
|
|
|
Regulatory transcription factors bind to . . . .
|
Regulatory transcription factors bind to . . . . proximal control elements
|
|
|
Enhancers - what they do
|
Stimulate transcription
|
|
|
Enhancers - How they do it
|
?
|
|
|
Activators
|
Regulatory Transcription factors that bind to enhancers
|
|
|
Enhancer-Activator complex
|
Enhanceosome
|
|
|
Housekeeping proteins
|
Made from genes that are always on. e.g. actin, tubulin
|
|
|
Silencers
|
Inhibit transcription
|
|
|
Mediator - function
|
A large multi-function protein that acts as a coactivator by serving as a bridge that bindsto activatoe proteins associated with the enhancer and to RNA polymerase, thereby linking enhancers to the components involved in initiating transcription at RNA polymerase II promoters
|
|
|
Mediator - process
|
- a group of activator proteins bind to their respective DNA control elements within the enhancer, forming a multiprotein complex called an enhanceosome
- Activator proeins caue DNA to bend, bringing enhancer closer to core promoter - Activators bind to Mediator, which facilitates correct positioning of RNA polymerase and the general transcription factors at the promoter site allowing transcription to begin |
|
|
Combinatorial Control
|
A model for DNA transcription which proposes that a relatively small number of different DNA control elements acting in different combinations can establish highly specific and precisely controlled patterns of gene expression in in different cell types. A gene is only fully expressed when all regulatory controls are set to on.
|
|
|
Domains of Regulatory Control Facors:
|
- a DNA binding domain
- a transcription regulatory domain (activation domain) |
|
|
motif
|
Secondary structure pattern in proteins that recognize specific DNA sequences, allowing them to fit tightly against the DNA surface in major groove
|
|
|
Response Elements
|
Different genes that recognize activators and can be turned on at the same time
|
