Question

E. coli grown in the presence of lactose, but absence of glucose, will use the enzyme beta-galactosidase to digest lactose. How are these cells different from cells which are grown in the absence of lactose and presence of glucose

Answer 1

Answer: Lac operon

Explanation: the same cells when grown in glucose media utilize the glucose as source if energy by blocking the activity of the enzyme beta- galactosidase. the operator site of the operon is blocked thereby preventing the activity of the collective functional genes.