試題詳解

56. The role of a metabolite that controls a repressible operon is to
(A) increase the production of inactive repressor proteins.
(B) bind to the repressor protein and activate it.
(C) bind to the repressor protein and inactivate it.
(D) bind to the operator region and block the attachment of RNA polymerase to the promoter.
(E) bind to the promoter region and decrease the affinity of RNA polymerase for the promoter.