Genes

Question 1

Where do regulatory proteins bind to?

Answer 1

• effector (in order to sense environment)

- operator (to regulate expression)

Question 2

What is a merodiploid?

Answer 2

partially diploid bacteria

Question 3

What does O^c mutated allele do?

Answer 3

allows for expression regardless of lactose presense

Question 4

What does cis-acting mean and what gene does it apply to?

Answer 4

gene can only affect genes around it (i.e ([__}/___)

O gene

Question 5

What does the I^s mutated allele do?

Answer 5

super repressor, blocks transcription = prevents expression on all operons

Question 6

What does trans-acting mean and what gene does it apply to?

Answer 6

gene can affect both operons

I gene

Question 7

How do you make merodiploid cells?

Answer 7

2 CO events between Hfr and F- removes F factor and some bacterial chromosomal segments

Question 8

What activates lac operon?

Answer 8

CAP

Question 9

What is the effector for CAP?

Answer 9

cAMP

Question 10

What happens when there is not enough glucose?

Answer 10

• ATP –> cAMP
• cAMP and CAP bind, forming complex
• complex binds to lac promoter, expression goes up

Question 11

What happens when there is a lot of glucose?

Answer 11

• ATP does not convert to cAMP
• complex does not form
• RNA polymerase binds ineffectively