What is lactose a compound of?
Lactose
Hence lactose is a compound of glucose and galactose.
The structural gene'Y'is said to produce a protein Lactose permiase which makes the cell permeable to Lactose. But the operon is already inside the cell and the protein is produced only after the Lactose enters into it. Then what is the use of making the cell permeable again. Is it for the future Lactose molecules to enter?