Question

The ara operon is an inducible operon that controls the breakdown of the sugar arabinose. When arabinose is present in a bacterium it binds to the protein AraC, and the complex binds to the initiator site to promote transcription. In this scenario, AraC is a(n) ________.

a) activator
b) repressor
c) inducer
d) inhibitor

Answer 1

In the presence of arabinose, the AraC protein acts as an activator for the ara operon, binding to the DNA to promote transcription.

Step-by-step explanation:

The ara operon controls the breakdown of the sugar arabinose and is considered an inducible operon. When arabinose is present, it binds to the protein AraC. This AraC-arabinose complex then binds to the initiator site to promote transcription. In this scenario, as AraC binds to the DNA to promote transcription in the presence of arabinose, it functions as an activator.