Question

The lac operon consists of regulatory regions such as the promoter as well as the structural genes lacZ, lacY, and lacA, which code for proteins involved in lactose metabolism. What would be the outcome of a missense mutation in one of the structural genes of the lac operon?

a) No effect on protein function
b) Loss of promoter activity
c) Altered protein function
d) Inhibition of transcription

Answer 1

A missense mutation in one of the lac operon's structural genes would likely produce an altered protein function, which can affect the process of lactose digestion in E. coli.

Step-by-step explanation:

A missense mutation in one of the structural genes of the lac operon, such as lacZ, lacY, or lacA, involved in lactose metabolism would most likely lead to altered protein function. Each of these genes codes for a protein vital in the process of lactose digestion.

If such a mutation resulted in a change of one amino acid in the enzyme, the consequence could range from benign to detrimental, depending on whether the change affected the protein's ability to function. A missense mutation does not typically affect the promoter activity or directly inhibit transcription, so options b) and d) are not correct. The effect on the protein function, which could be partial or complete, thus directly corresponds to option c) Altered protein function.