In the lac operon, which of the following genes codes for the enzyme that increases the permeability of the cell to -galactosides?

Step-by-step solution

In the lac operon, the y gene codes for the enzyme permease. Permease is responsible for increasing the permeability of the cell membrane to -galactosides (such as lactose), allowing them to enter the cell. The z gene codes for -galactosidase (which hydrolyses lactose), the a gene codes for transacetylase, and the i gene codes for the repressor protein. Selecting the z gene is a common mistake made by students who recall it as the primary structural gene but forget its specific enzymatic function. Answer: y gene