Regulation of gene expression

Question 1

Amount of protein is determined by the rate of (3)

Answer 1

transcription
translation
degradation of mRNA or protein

Question 2

activity of a protein is determined by (2)

Answer 2

protein cleavage
protein modifications

Question 3

A common way for cells to regulate gene expression

Answer 3

controll transcriptioin

Question 4

transcription of a gene is off/low

Answer 4

absence of activator or presence of repressor

Question 5

transcription is on/high

Answer 5

presence of activator/lack of repressor

Question 6

transcription in prokaryotes

Answer 6

organize related genes into operons

Question 7

transcription in eukaryotes

Answer 7

have shared regulatory sequences

Question 8

operon

Answer 8

functionally related genes

Question 9

what do operons produce

Answer 9

multiple proteins from a single mRNA transcript

Question 10

inducible operon

Answer 10

turned off until the products of gene expression are needed

Question 11

repressible operon

Answer 11

turned on until the products of gene expression aren’t needed

Question 12

An famous example of an inducible operon

Answer 12

lac operon

Question 13

When is the lac operon repressed

Answer 13

when lactose is absent

Question 14

What type of operon is the trp operon

Answer 14

repressible

Question 15

when is the trp repressor active

Answer 15

when tryptophan is bound

Question 16

The gal operon is an inducible that contains genes necessayr for galactose metabolism What is not true about the gal operon

Answer 16

galactose binds to the operator

Question 17

How are eukaryotic cells transcription regulated?

Answer 17

by proteins that bind to enhancers located in and around genes

Question 18

what are enhancers

Answer 18

DNA sequences in the regulatory regiion of a gene that can increase transcription from a nearby promoter

Question 19

Enhancer-bindiing proteins promote what

Answer 19

transcription

Question 20

Location of enhancers

Answer 20

may be distant from the promoter

Question 21

mediator proteins

Answer 21

makes all the factors come together

Question 22

more transcription factors effect on producing gene

Answer 22

more gene produced

Question 23

Cell differentiation

Answer 23

process by which cells become specialized

Question 24

selective expression of different genes

Answer 24

can give rise to different cell types

Question 25

situ hybridization

Answer 25

used to detect the presence and location of mRNA from one specific gene

Question 26

microarrays allow for what

Answer 26

global analysis of gene expression

Question 27

Single cell RNA-seq

Answer 27

can be used to characterize the transcriptome of complex tissues

Question 28

RNA sequence reveals

Answer 28

gene expression varies even in seemingly homogenous tissues

Question 29

Two histone modifications

Answer 29

acetylation and methylation

Question 30

acetylation

Answer 30

transcriptional activation

Question 31

methylation

Answer 31

transcriptional repression

Question 32

DNA modification

Answer 32

cytosine methylation

Question 33

cytosine methylation

Answer 33

transcriptional repression

Question 34

nucleosome

Answer 34

packaging DNA unit

Question 35

methylation of cytosines in

Answer 35

CpG islands represses transcription

Question 36

epigenetic modifications

Answer 36

change chromatin structure

Question 37

Environmental factors

Answer 37

affect DNA methylation and have effects on health

Question 38

Alternative splicing

Answer 38

a form of differential gene expression

Question 39

microRNAs

Answer 39

regulate eukaryotic gene expression by blocking translation or promoting mRNA degradatioin

Question 40

three facts about miRNA

Answer 40

1. tissue and developmental stage specifific miRNA exprfession 2.more than 60% of genes regualted by miRNA 3. each miRNA can regulate multiple mRNA targets

Question 41

microRNAs in plants

Answer 41

regulate gene expression

Question 42

Long non-coding RNAs (lncRNA)

Answer 42

regulate gene expression such as guiding, scaffolding

Question 43

postranslational mechanisms for regulating gene expression (5)

Answer 43

1. reversible modifications like phosphorylation 2. regulation of protein folding (chaperones) 3. interactions with small molecules like Ca2+ 4. proteolytic cleavage 5. ubiquitin-mediated protein degradation