The lac operon is an operon, or group of genes with a single promoter (transcribed as a single mRNA). The genes in the operon encode proteins that allow the bacteria to use lactose as an energy source.

Why is lac operon a gene?

The duo noted that the lac operon contains three genes that encode proteins involved in lactose metabolism. These are referred to as lac z, lac y, and lac a. The lac z gene encodes beta-galactosidase, the lac y gene encodes a permease, and the lac a gene encodes the transacetylase enzyme.

What is the lac operon an example of?

The lac operon is the classical example of an inducible circuit which encodes the genes for the transport of external lactose into the cell and its conversion to glucose and galactose.