Question

The cAMP-CAP complex and RNA polymerase bind more efficiently to the lac operon together than either does alone. What term is applied to this increased efficiency of binding?

Answer 1

The increased efficiency of binding between the cAMP-CAP complex and RNA polymerase to the lac operon is called synergistic binding or catabolite activation, enabling efficient initiation of transcription in the absence of glucose.

Step-by-step explanation:

The term applied to the increased efficiency of binding between the cAMP-CAP complex and RNA polymerase to the lac operon is known as synergistic binding or catabolite activation. This occurs because the cAMP-bound CAP (catabolite activator protein), when attached to the promoter region, induces the DNA to bend, making it easier for RNA polymerase to bind to the DNA and initiate transcription. Specifically, in the absence of glucose, cAMP levels rise and bind to CAP, enabling this complex to attach to the lac operon promoter. The association with the promoter removes the lac repressor from the operator, facilitating transcription and allowing the cell to metabolize lactose via the enzymes produced by the lac operon.