Sets 16

Question 1

how many RNA pol are used for transcription in eukaryotes?

Answer 1

3

Question 2

what RNA pol is used for protein transcription

Answer 2

RNA pol II

Question 3

what is the core promoter and what is it composed of?

Answer 3

a part of the promoter close to the gene coding region; it has the +1 region which transcription starts and the the TATA box

Question 4

where is the TATA box and how many nucleotides does it have?

Answer 4

at the -30 region and has about 7 nucleotide

Question 5

what are the 4 cis acting regulatory regions ?

Answer 5

core promoter( TATA box)
CAAT box (@ 74-94)
GC box (@ 74-94)
Enhancer

Question 6

what is an enhancer ?

Answer 6

a reg site on DNA that can be close or far way from the core promoter and increase transcription by 100x

Question 7

what 2 basal factors must bind to core promoter ?

Answer 7

TATA box binding protein (TBP)
TBP-associated factors (TAF)

Question 8

how does TAF, RNA Pol & TBP bind to the promoter ?

Answer 8

TBP bind to the promoter and the TAFs bind to the TBP and RNA pol bind to all

Question 9

what are transcription factors

Answer 9

certain proteins that can control the rate of transcription by binding to the DNA

Question 10

what binds to enhancers ?

Answer 10

transcriptional activators

Question 11

what are the two domains on the activators ?

Answer 11

the DNA binding domain
transcription activation domain

Question 12

what can bind to activators what do they do ?

Answer 12

co activators and they can unwrap the DNA on the promoter region

Question 13

what is lightly packed DNA

Answer 13

Euchromatin

Question 14

what is tightly packed DNA?

Answer 14

Heterochromtin

Question 15

can promoters have multiple enhancers

Answer 15

yes

Question 16

what is needed to be an activator ?

Answer 16

you need to be a dimer to be able to bind to the enhancer

Question 17

what is an example of a co activator

Answer 17

steroid hormones

Question 18

what does a co-activator do ?

Answer 18

binds to the activator and changes its shape to be able to bind to DNA enhancer

Question 19

How does an activator stabilize transcription ?

Answer 19

by interacting with the other proteins TBP & TAF and RNA pol

Question 19

what 4 things must the activator do to be able to turn on the gene transcription

Answer 19

1. Binds to the hormone
2. Become a dimer
3. be in nucleus
4. bind to enhancer

Question 19

what do transcriptional repressors do ?

Answer 19

its lowers transcriptional activity

Question 20

what are the two ways that transcriptional repressors lower transcription?

Answer 20

binding to enhancer
binding to activator

Question 21

what 2 things can a co-repressor do ?

Answer 21

1.interact with the protein and RNA pol and prevent them form the promoter
2. tightin and wrap DNA ( histones)

Question 22

why is DNA wrapped tightly

Answer 22

bc of lysine positive charge and phosphate negative charge

Question 23

what 2 things affect gene expression?

Answer 23

1. chromatin structure 2. DNA methylation patterns

Question 24

what are the two type of chromatin structure modifications?

Answer 24

1.Acetlyation 2. Methylation

Question 25

what does acetylation on the chromotin do?

Answer 25

it has a negative charge so it interfers with the Histone and DNA electric charge and unwinds it a little to help transcription

Question 26

what does methylation on the chromatin do ?

Answer 26

methylation on the chromatin bring in other factors that hold "lock in" the chromatin in place which keeps it tight and keep it permanently OFF

Question 27

what is dark bands ?

Answer 27

heterochromatin meaning genes in region is not transcribed

Question 28

what are TAD's (Topological associated domains)

Answer 28

puts regulator elements in a loop so certain enhancers and promoters can interact with another

Question 29

what is DNA methylation ?

Answer 29

block of C&G rich islands that can be methylated and stop transcription there

Question 30

what is epigenetic phenomena ?

Answer 30

a change in gene expression that is not related to sequence changes (methylation)

Question 31

what is gene imprinting ?

Answer 31

dna methylation being passed on the children