Regulation of Gene Expression Flashcards
Genes can generally be classified into 2 groups: _______ and _______ genes.
1) housekeeping genes
2) regulated genes
These genes are involved in basic cellular functions and are constitutively expressed and not regulated.
Housekeeping Genes
These genes are only required in certain cell types or under certain conditions and are subject to various control mechanisms.
Regulated Genes
________: a multi step process that ultimately results in the production of a functional gene product (RNA or Protein).
Gene Expression
For most genes, the main site of control is ___________ of _____ to ______.
Transcription
DNA
RNA
Beta-Actin is found in all tissues and is involved in basic cellular functions. Beta-Actin is an example of a ________ gene.
Housekeeping gene
DNA in __________ cells are circular.
Prokaryotic
DNA is transcribed into _______ which is then ________ into a _________.
mRNA
Translated
Protein
In prokaryotes, the amount of protein that is expressed is regulated at a __________ level.
Transcriptional level
Although there are other mechanisms of regulation of gene expression in prokaryotes, the primary means of regulation is accomplished via ______.
Transcriptional control
________ genes are not always expressed. They are only expressed when necessary.
Structural
The goal of any organism (From a biochemical perspective) is to ______ _____.
Conserve energy
What are the 2 basic types of operons?
1) Repressible
2) Inducible
Repressible operons are usually _____.
On
The Lactose Operon is a ________ operon.
Inducible
_______ is the preferred carbon source for E. coli.
Glucose
An operon consists of a ______ region and an _______.
Promoter
Operator
The Repressor Protein is ALWAYS expressed. Which gene is the repressor protein in Lactose Operon expression in Prokaryotes?
lacI
Control of gene expression in __________ is more complex and includes regulation at __ different levels.
Why is it more complex?
Eukaryotes
5
More complex because we need more variety cell types
List the 5 levels of regulation in Eukaryotic Gene Expression:
Transcriptional Post-Transcriptional Translational Post-Translational Epigenetics
_________: ‘around genetics’
Epigenetics
Regulatory sequences of DNA are usually embedded in the ____________ region of the genome.
They are called ________ because they influence expression of genes only on the same chromosome.
Noncoding
Cis-acting
Trans-acting proteins are __________.
Proteins
Transcription factors are are __________ regulators.
Trans-acting
Binding of trans-acting regulators to DNA is achieved by one of the following:
_____
_____
_____
1) Zinc Finger
2) Leucine zipper
3) Helix-turn-helix in the protein
DNA sequences that increase the rate of initiation of transcription are called _______.
Enhancers
Enhancers are typically found on __________.
The same chromosome.
__________can be close to the gene they are controlling or thousands of base pairs away.
Enhancers
Where can enhancers be located?
Upstream
downstream
Or even within intron regions or other chromosomes
__________ can be brought close to the basal promoter by bending of the DNA molecule.
Enhancers
True or False:
Enhancers can act in a tissue specific manner
True
PEPCK gene expression is induced by _________.
Cortisol
PEPCK is an enzyme from the ___________ pathway.
Gluconeogenic
True or False: steroid hormones are fat soluble
TRUE
GRE stands for:
Glucocorticoid response element
Over ___% of genes in humans undergo alternative splicing.
An example is _________: an actin filament-binding protein, interaction with the cytoskeleton in most cells, and the contractile apparatus of muscle cells, undergoes tissue specific alternative splicing to produce multiple isoforms of the protein.
60
Tropomyosin
The following are all examples of which type of control? Alternative splicing, mRNA editing, mRNA stability….
Post-transcriptional control
Apo B mRNA is made in the _____ and in the ____ _______.
In the _______ only, the C residue in the CAA codon for glutamine is delaminated to U, changing the sense codon to a nonsense or stop codon.
Liver
Small intestine
Intestine
RNAi (RNA Interference) is a increasing field of research in reducing _____ _______.
Gene expression
Neovascular AMD is triggered by overproduction of ________.
(VEGF) vascular endothelial growth factor
Overproduction of VEGF may lead to the development of ____________ behind the retina.
Excess blood vesssels sprouting
siRNAs, when introduced into a cell from exogenous sources can trigger _______, ultimately silencing certain gene expressions.
RNAi
When elF2 is _________, translation is blocked.
Phosphorylated
During post-translational control, protein folding is directed by _______.
Chaperones
_________ are regions in DNA rich in CG that are prone to modifications.
CpG islands
__________: mobile segments of DNA that move in a random manner from one site to another on the same or a different chromosome.
Movement is mediated by _________, an enzyme encoded by the Tn itself.
Movement can be ________ or _________.
Transposons (Tns)
Transposase
Direct or Replicative
Transposition has contributed to the structural variation in the genome but it is also associated with disease, examples of which include: (name 3)
Hemophilia A
Duchenne muscular dystrophy
Antibiotic resistance in bacteria
