Which of the following terms best characterizes catabolite repression associated with the lac operon in E.coli? A)constitutive B)negative control C)repressible system D)positive control E)inducible system

Question

Quizplus · Accepted Answer

Catabolite repression associated with the lac operon in E. coli is a positive control mechanism. Catabolite activator protein (CAP) binds to the lac operon promoter in the presence of cyclic AMP (cAMP), which increases transcription of the operon. When glucose is present, cAMP levels decrease and CAP cannot bind to the promoter, leading to decreased transcription of the operon. Therefore, catabolite repression is a positive control mechanism that increases transcription in the absence of glucose and decreases transcription in the presence of glucose.

Which of the Following Terms Best Characterizes Catabolite Repression Associated