In E. coli, lactose binds with: a. the lactose operon repressor, preventing it f
ID: 70966 • Letter: I
Question
In E. coli, lactose binds with:
a. the lactose operon repressor, preventing it from binding to the operator. This allows the lacZ and lacY genes to be transcribed.
b. the lactose operon operator, preventing it from binding to the repressor. This allows the lacZ and lacY genes to be transcribed.
c. the lactose operon repressor, helping it bind to the operator. This prevents the lacZ and lacY genes from being transcribed.
d. the lactose operon operator, preventing RNA polymerase from being recruited. This prevents the lacZ and lacY genes from being transcribed.
e. the lactose operon operator, recruiting RNA polymerase. This allows the lacZ and lacY genes to be transcribed.
Explanation / Answer
a. the lactose operon repressor, preventing it from binding to the operator. This allows the lacZ and lacY genes to be transcribed.
The repressor does not allow the transcription of the enzymes needed for lactose breakdown. So lactose binds to the repressor and inactivates it. This prevents the repression of transcription and the enzymes are synthesized.