Question

what does lac operon means?

Answer 1

The Lac operon is an operon present in some enteric bacteria including E.coli to metabolise lactose sugar.
Lac operon usually consist of a regulatory gene, the i gene and three structural genes namely z, y and a.
The i gene codes for a regulatory protein. The z gene codes for an enzyme beta- galactosidase, which hydrolise lactose in to glucose and galactose, the y gene codes for permease enzyme by which the permeability of cell to beta- galactosidase increases. Third structuaral gene, the a gene codes for transacetylase . Hence all these genes present in lac operon are necessary to metabolise lactose sugar in E. coli