16. Regulation of Expression

The protein that binds to the operator of the lac operon to prevent transcription is encoded by which gene?

The lac operon is a(n) _______________ operon that is typically ______________.

In the lac operon, which of the following functions does the lactose molecule serve:

If E. coli bacteria are grown in the presence of lactose:

Why are the genes involved in lactose metabolism considered to be an operon?

a. They occupy adjacent locations on the E. coli chromosome.

b. They have a similar function.

c. They are all required for normal cell function.

d. They are all controlled by the same promoter.

Evaluate these statements about regulation of the lac operon. Select True or False for each statement.

T/FThe lac operon is transcribed at the highest rate when extracellular glucose and lactose are abundant.

T/FThe repressor protein is bound to DNA of the operator when lactose is present.

T/FA mutation in the operator is likely to prevent transcription of the lac operon under any condition.

T/FA mutation that alters the catabolite activator protein is predicted to alter the regulation of many different operons.