In the regulation of the lac operon in Escherichia coli, cyclic AMP
A) is a small metabolite that binds with lactose to increase transcription of the lac operon.
B) increases in concentration when glucose is present in the cell.
C) is produced from glucose to inhibit the binding of RNA polymerase to the lac operon.
D) is involved in the positive regulation of the lac operon via its allosteric interaction with the catabolite activator protein.
E) prevents the RNA polymerase from binding to the promoter region via its allosteric interaction with the catabolite activator protein.

Question

Quizplus · Accepted Answer

Cyclic AMP (cAMP) is involved in the positive regulation of the lac operon by binding to the catabolite activator protein (CAP), which then can bind to the DNA and facilitate RNA polymerase action, enhancing transcription of the lac operon when glucose levels are low.

In the Regulation of the Lac Operon in Escherichia Coli