Regulation of Transcription

Question 1

four types of DNA binding regulatory proteins

Answer 1

helix turn helix
zinc fingers
leucine zippers
helix loop helix

Question 2

these proteins regulate genes involved in development

Answer 2

helix turn helix

Question 3

these proteins are steroid hormone receptors

Answer 3

zinc finger motif

Question 4

these proteins regulate cell division genes

Answer 4

leucine zipper

Question 5

these proteins regulate immune system genes

Answer 5

helix loop helix

Question 6

examples of DNA binding domains

Answer 6

homeodomains

Question 7

how do DNA binding domains interact with the major groove of DNA

Answer 7

H-bonds
salt-bridges
hydrophobic interactions

Question 8

two characteristics of DNA binding domains

Answer 8

rich in alpha helices

can bind to promoters and enhancer sequences

Question 9

have an acidic patch that allows interaction with other transcription factors

Answer 9

activation domain

Question 10

what can activation domains bind to

Answer 10

other transcription factors
RNA polymerase II
activators

Question 11

genes are not transcribed unless an activator is present

Answer 11

positive control

Question 12

positive control that turns genes on

Answer 12

activation

Question 13

positive control that turns genes off

Answer 13

deactivation

Question 14

genes are always transcribed unless a repressor is present

Answer 14

negative control

Question 15

negative control that turns genes off

Answer 15

repression

Question 16

negative control that turns genes on

Answer 16

derepression

Question 17

a unit of genetic function consisting of groups of genes with related functions where a single promoter and operator serve to control the expression of all genes in that unit together

Answer 17

operons

Question 18

where to operons primarily occur

Answer 18

in prokaryotes and nematodes

Question 19

an inducible operon where transcription is stimulated in the presence of lactose

Answer 19

lac operon

Question 20

a repressible operon where transcription is inhibited in the presence of tryptophan

Answer 20

trp operon

Question 21

lactose is made up of

Answer 21

galactose and glucose

Question 22

what form of lactose binds to the lac operon repressor

Answer 22

allolactose

Question 23

regulatory genes for the lac operon code for

Answer 23

repressor protein

CAP

Question 24

the lac repressor exhibits what kind of motif

Answer 24

helix turn helix

Question 25

what three enzymes are coded for in the lac operon

Answer 25

Beta-galactosidase permease transacetylase

Question 26

in conjuction with cAMP, serves as an indicator of glucose availability

Answer 26

CAP

Question 27

when there is no glucose and there is lactose

Answer 27

increase in cAMP and binding to CAP | 50x increase in transcription of lac genes

Question 28

when there is glucose and lactose present

Answer 28

decreased cAMP and no binding to CAP | weak transcription

Question 29

when there is glucose and no lactose present

Answer 29

decreased cAMP and no binding to CAP | lac repressor present and no transcription

Question 30

how is trp operon different from lac operon

Answer 30

the presence of tryptophan causes the inhibition of the operon instead of its activation

Question 31

affect the configuration of chromatin and gene expression

Answer 31

chemical modification of histone tails

Question 32

how are histone tails modified

Answer 32

attachement of acetyl group to lysines

Question 33

protein recruited to keep histones deacetylated

Answer 33

HDAC

Question 34

activator protein binding recruits this protein which acetylates histones

Answer 34

HAT

Question 35

histone modification that prevents transcription

Answer 35

methylation at lysines and arginines residues

Question 36

what is the epigenetic regulation of histones in DNA

Answer 36

addition of methyl groups to cytosines of DNA

Question 37

limits body weight and cell proliferation

Answer 37

H19

Question 38

insulin like growth factor

Answer 38

IGF2

Question 39

on the maternal chromosome and enhancer drives expression of ____ and an insulator protein blocks ____expression

Answer 39

H19 and IGF2

Question 40

on paternal chromosome, methylation inactivates the ICR and block the ____ expression, enhancer drives ____expression

Answer 40

H19 and IGF2

Question 41

if H19 is mutated or missing this disease develops

Answer 41

angelman syndrome

Question 42

if IGF2 is mutated or missing this disease develops

Answer 42

prader-willi syndrome

Question 43

what binds to the TATA box

Answer 43

transcription factors

Question 44

what are close to the promoter

Answer 44

proximal control elements

Question 45

may be far away from a gene or even in an intron

Answer 45

enhancers

Question 46

what binds to enhancers

Answer 46

activators

Question 47

bind to silencer region of the DNA to inhibit expression of a particular gene

Answer 47

repressors

Question 48

describe the process of mRNA degradation

Answer 48

miRNA folds onto itself dicer protein claves miRNA into smaller fragments miRNA binds to protein complex miRNA protein complex binds with mRNA mRNA is degraded or translation is blocked