Gene Expression

Question 1

What is euchromatin? colour?

Answer 1

open relaxed conformation. light bands

Question 2

heterochromatin? colour?

Answer 2

closed condensed formation. dark bands

Question 3

How are histones modified in euchromatin?

Answer 3

hyper acetylated

hyper methylated

Question 4

How are histones modified in heterochromatin?

Answer 4

hypoacetylated,

hypo methylated

Question 5

What happens when DNA is methylated?

Answer 5

silencing of genes

Question 6

where is DNA usually methylated?

Answer 6

CpGs around promoters

Question 7

gene expresison makes two things:

Answer 7

proteins and RNA products

Question 8

where do you normally find heterochromatin?

Answer 8

closer to nuclear membrane as it’s less active

Question 9

what needs to happen to chromatin to give access to transcriptional machinery?

Answer 9

remodelling via chemical modification (epigenetic markers)

Question 10

how do you get protein diversity from genes? 2 reasons

Answer 10

1. more than one promoter

2. alternative splicing

Question 11

non-coding RNAs like siRNA involved with?

Answer 11

mRNA degradation

Question 12

miRNAs can be involved in?

Answer 12

repressing mRNA translation

Question 13

transcription begins where?

Answer 13

TATA box/promoters

Question 14

3 kinds of non-coding RNAs

Answer 14

long non-coding RNAs
short-interfering RNAs
micro RNAs

Question 15

4 things long non-coding RNAs can do?

Answer 15

1. decoy
2. scaffold (enhance or inhibit)
3. guide
4. enhancer

Question 16

siRNAs single or double stranded?

Answer 16

double, uncleaved

Question 17

What do cis and trans acting elements affect in genes?

Answer 17

Cis - DNA

Trans - proteins