Question

In gene regulation, what is the usual state of a repressible operon?

Answer 1

The usual state of a repressible operon is in the "on" or active state. This means that the genes in the operon are transcribed and translated to produce the corresponding protein products. In a repressible operon, the presence of a specific corepressor molecule (such as a metabolite or end product) is required to turn off the operon. The corepressor molecule binds to a repressor protein, causing it to bind to the operator region of the operon. This blocks the RNA polymerase from binding to the promoter and initiating transcription, effectively repressing the operon.