Extracellular glucose inhibits transcription of the lac operon by
A) weakening the binding of repressor to the operator.
B) inhibiting RNA polymerase from opening the strands of DNA to initiate transcription.
C) reducing the levels of intracellular cAMP.
D) strengthening the binding of repressor to the operator.
E) activating adenylyl cyclase.

Question

Quizplus · Accepted Answer

Extracellular glucose reduces the levels of intracellular cAMP by inhibiting adenylyl cyclase, which in turn decreases the activity of cAMP-CRP, a complex necessary for the efficient transcription of the lac operon.

Extracellular Glucose Inhibits Transcription of the Lac Operon by