Question: 105. The lactose present in the growth medium of bacteria is transported to the cell by the action of:
(1) Beta-galactosidase
(2) Acetylase
(3) Permease
(4) Polymerase
Answer: Option (3)
Explanation:
In bacteria, the lac operon controls the metabolism of lactose.
The gene lacY codes for permease, which is a membrane protein.
Permease facilitates the transport of lactose from the growth medium into the bacterial cell.
Beta-galactosidase breaks lactose into glucose and galactose after it enters the cell.
Acetylase is involved in detoxification and polymerase is involved in nucleic acid synthesis.
Therefore, lactose is transported into the cell by the action of permease.