Regulation of genes, Genomes, BioTechnology

Question 1

What are Transcription factors, what do they control?

Answer 1

Repressors and activators
control gene activity

Question 2

What are Eukaryotic promoters and what is a common sequence

Answer 2

Eukaryotic promoters are DNA regions where RNA poplymerase binds to initiate transcription.
A common sequence is a TATA box, rich in AT base pairs

Question 3

what do general transcription factors bind to? What happens after?

Answer 3

bind to the core promoter, then RNA polymerase ll binds and initiates trancription.

Question 4

What do enhancers bind and what do silencers bind?

Answer 4

enhancers bind activators
silencers bind repressors

Question 5

How do Prokaryotes conserve their energy?

Answer 5

They only make proteins when they’re needed

Question 6

What levels are changed as enviromental conditions change?

Answer 6

Rapidly changes expression levels.
EX: lactose catabolism in E. coli

Question 7

What three proteins are required in uptake and metabolism of lactose and what do they do?

Answer 7

• β-galactoside permease
• β-galactosidase—hydrolyses lactose
• β-galactoside transacetylase—transfers acetyl groups to β-galactosides; role is unclear

Question 8

What happens to the mRNA level as lactose is added?

Answer 8

The mRNA level increases

Question 9

what are inducible genes?

Answer 9

Inducers that stimulate trancription

Question 10

What are constitutive genes?

Answer 10

genes that are expressed most the time at a constant rate

Question 11

What are the three genes for lactose enzymes?

Answer 11

• Adjacent on the chromosome
• Share a promoter
• transcribed together

Question 12

what is the operator?

Answer 12

a short stretch of DNA near the promoter that controls transcription

Question 13

where do repressor proteins bind and what does it block?

Answer 13

at the operator and blocks transcription