Question

In lac operon, 'Z' and 'Y' genes code for which enzymes? Also mention their functions.

Hint:

Z = β-galactosidase (breaks lactose), Y = Permease (transports lactose).

Answer 1

Step 1: Background.
The lac operon in E. coli regulates lactose metabolism. It has structural genes (Z, Y, A) controlled by a promoter, operator, and regulator gene.

Step 2: Role of Z and Y genes. \[\begin{array}{rl} \bullet & \text{Z gene: Codes for β-galactosidase enzyme.} \\ \bullet & \text{Function: Hydrolyses lactose into glucose and galactose.} \\ \end{array}\] \item Y gene: Codes for Permease enzyme. \[\begin{array}{rl} \bullet & \text{Function: Increases permeability of the cell membrane to allow entry of lactose into the bacterial cell.} \\ \end{array}\] \end{itemize}

Step 3: Conclusion.
Thus, in the lac operon, Z and Y genes play key roles in lactose utilization: Z (breakdown) and Y (transport).