Quiz 8- CH 17

Question 1

how much gene expression=

Answer 1

how much mRNA/protein from a gene

Question 2

Control regulation

Answer 2

cell cycle checkpoints
without regulation mechanisms will not occur properly

Question 3

transcriptional unit

Answer 3

one way we can regulate

Question 4

template strand

Answer 4

compliment to RNA
provides the template

Question 5

non-template strand

Answer 5

coding strand
same sequence as RNA

Question 6

Lac Operon

Answer 6

inducible promoter
regulator upstream that creates a repressor that binds to operator
allolactose binds to repressor, changing its shape, which removes it from operator- active operator
when there is no more lactose, repressor binds to operator and stops transcription

Question 7

differences in eukaryotic gene expression

Answer 7

1. each gene has its own promoter
2. chromatin structure affects eukaryotic gene expression
3. nuclear membrane separates transcription from translation

Question 8

many levels of gene regulation

Answer 8

1. transcription regulation
2. mRNA processing
3. Regulation of mature mRNA
4. translational
5. post-translational

Question 9

gene expression regulated by promoter

Answer 9

basal trans. apparatus= minimal transcription
transcription regulator proteins= normal transcription
regulatory proteins (TFs) can be activators or repressors

Question 10

activators bind

Answer 10

enhancers

Question 11

repressors bind

Answer 11

silencers

Question 12

GAL4 EX. of transcriptional activator

Answer 12

UAS= enhancer
in absensce of glucose GAL4 is blocked from activating transcription by GAL80
in presence of glucose it binds to GAL3, brings conformational change of GAL80 and Gal4 can interact to stimulate transcription

Question 13

insulator

Answer 13

DNA sequence that blocks the effect of enhancers in a position dependent manner
insulators repress enhancers
if you repress insulator=greater production of enhancer

Question 14

change in chromatin that can affect gene expression

Answer 14

histone modification
chromatin remodeling
DNA methylation

Question 15

euchromatin=

Answer 15

open

Question 16

heterochromatin=

Answer 16

closed

Question 17

nucleosome=

Answer 17

histone + DNA

Question 18

Histone modification

Answer 18

histone N-tail acetylation, phosphorylation and methylation of specific lysines

Question 19

acetylation

Answer 19

activated
DNA less tightly packed, more accesible

Question 20

methylation

Answer 20

deactivated

Question 21

Acetylated lysines create…

Answer 21

binding sites for specific activators

Question 22

Chromatin remodeling

Answer 22

catalytic reaction by chromatin remodeling complexed
changes arrangement of nucleosomes
after is more accessible to RNA polymerase
shifting/removal of nucleosomes results in diff DNA becoming accessible

Question 23

DNA methylation

Answer 23

leads to inhibition of transcription
removed before transcrition initiation or remains methylated for long term-silencing
attracts DNA deacetylases
imprinting

Question 24

imprinting

Answer 24

maternal chromosome- ICR is on; enhancer deactivated
paternal- ICR off; enhancer activated
enhances body size of organism because IGF2 is expressed

Question 25

RNA Interference

Answer 25

target other molecules in environment, when they bind they are chopped up by dicer OR they bind and inhibit the molecule and decrease expression

Question 25

ICR

Answer 25

imprinting control region
insulator that cannot function when methylated

Question 26

miRNA

Answer 26

imperfectly matched to target sequence
regulators of endogenous genes

Question 27

siRNA

Answer 27

perfectly matched to target sequence
defense against genomic invaders