Chapter 18 Eukaryotic Transcription

Question 1

Compare and contrast prokaryotes and eukaryotes: where does transcription occur in eukaryotes?

Answer 1

nucleus

Question 2

Compare and contrast prokaryotes and eukaryotes: What occurs simultaneously in prokaryotes?

Answer 2

transcriptiona nd translation

Question 3

How many RNA polymerases do eukaryotes use?

Answer 3

3

Question 4

Contrast RNA polymerase 1 and RNA polymerase 3

Answer 4

RNA polymerase 1- transcription of rRNA, no TATA
RNA polymerase 3- transcription of tRNA and 5S rRNA, no TATA

Question 5

How do insulators and enhancers function?

Answer 5

insulators block enhancers by moving inbetween it and the gene

Question 6

Are enhancers cis-regulatory or trans-regulatory? Do they act over long or short distances? How many transcription factor binding sites do they have? Are they evolutionarily conserved?

Answer 6

-cis
-longer distances
-multiple sites
-yes

Question 7

The GAL system in yeast is only transcribed when __________

Answer 7

galactose is prsent

Question 8

What is the enhancer on the GAL operon? What is the transcriptional factor?

Answer 8

UAS (upstream activating sequence), GAL4

Question 9

What happens in the absence of galactose? What happens in the presence?

Answer 9

absence- GAL180 binds to GAL 4and represses expression

Question 10

What happens in the presence of galactose?

Answer 10

GAL3 binds to GAL 180 and makes a allosteric conformation, removes GAL 180 and transcription occurs

Question 11

What happens when GAL4 binds to UAS?

Answer 11

Conformational change and the strand folds in on itsef
-recruits TF11D (binds to TBP on it)
-binds to mediator

Question 12

What accumultaes when glucose is high? What does it bind to?

Answer 12

MIG 1, binds to enhnacer site and recruits TUP1

Question 13

What is TUP1, and what does it do?

Answer 13

core repressor, HDAC and represses GAL