BIOS 2600 Exam III Week 1 (Prok and Euk Gene Regulation)

structural genes

genes that encode proteins used in metabolism/biosynthesis, or that play a structural role in the cell

regulatory genes

genes that encode RNA or protein which interact with DNA sequences and affect transcription/translation

constitutive genes

continually expressed, not regulated

regulatory elements

affect the expression of DNA sequences to which they are physically linked

positive control

processes that stimulate gene expression

negative control

processes that inhibit gene expression

forming hydrogen bonds with DNA bases

How do amino acids in DNA-binding proteins interact with DNA?

operon

a group of bacterial structural genes that are transcribed together, along with their promoter and additional sequences that control their transcription

overlaps the 3’ end of the promoter and the 5’ end of the first structural gene

where is the operator located?

inducible operons

transcription normally OFF

repressible operons

transcription normally ON

allosteric proteins

proteins that change shape upon binding to another molecule (ex. a repressor protein)

inactive repressor

the regulator protein that acts on a negative repressible operon is synthesized as a(n)…

negative inducible

what kind of operon is the lac operon?

B-Galactosidase

lacZ encodes…

permease

lacY encodes…

transacetylase

lacA encodes…

coordinate injunction

the simultaneous synthesis of several proteins stimulated by a specific molecule, the inducer, (think lac operon) is called…

allolactose

what acts as the inducer in the lac operon?

positive control

what kind of control is catabolite repression?

little transcription

what is the affect of high glucose levels on the lac operon?

negative repressible

what kind of operon is the trp operon?

it can’t bind to the operator, and transcription takes place

what happens to the trp repressor in the absence of tryptophan?

attenuation

_____ is the premature termination of transcription

some distance from the gene it affects

where are enhancers found?

antisense RNA

_____ controls gene expression by binding to sequences on mRNA and inhibiting its translation.

riboswitches

regulatory sequences where regulatory molecules can bind and affect gene expression by influencing the formation of secondary structures in the mRNA

active, closed

Sensitivity to DNase I in regions near transcriptionally _____ genes indicates that the chromatin in these regions assumes a(n) ______configuration before transcription.

chromatin-remodeling complexes

transcription factors/regulatory elements that alter chromatin structure without altering the chemical structure of the histones directly are…

acetylation

histone modification that usually stimulates transcription

methylation

histone modification that can either activate or repress transcription, depending on which histone is modified

ChIP

This technique allows researchers to determine the locations within the genome where a specific protein interacts with DNA.

methylated, unmethylated

Heavily _______ DNA is associated with the repression of transcription in vertebrates and plants, whereas transcriptionally active DNA is usually ________in these organisms.

the basal transcription apparatus

many transcription factors in eukaryotes stimulate transcription by interacting with…

insulators

DNA sequences that block the effects of enhancers in a position-dependent manner (lie between enhancer and promoter)

shortening, removal

mRNA degradation most commonly begins with the ____ of the polyA tail, which leads to the____ of the 5’ cap.

siRNA

RNAs that degrade mRNA by cleavage

miRNA

RNAs that lead to the inhibition of translation

degradation, inhibition

RNA silencing leads to the _____ of mRNA or the _____ of translation/transcription

3’ UTR

in RNA silencing, siRNAs and miRNAs usually bind to what?