Question

Question #6f334

Answer 1

You're right it stops functioning, but it may be induced to function by lactose in the absence of glucose. To be sure, lactose induces transcription by binding to a receptor on the repressor protein transcribed by the `lacI` gene.

Hence, it is an inducible operon.

Glucose only blocks transport of lactose into the cell or prevents an activator protein `cAMP-CAP` from binding to the promoter region to excite transcription levels.