lac operon summary
Repressor prevents gene expression (polymerase to transcript). when glucose is scarce...the inducer molecule allolactose appears in the cell then binds to repressor molecule and inactivates it. RNA polymerase can now transcribe the operon. three of the lac operon genes get transcribed into Mrna. Ribosomes then bind to Mrna and the three proteins are translated. Beta galactosidase, lactose permease and galactoside transacetylase. The induction of the lac operon enables the bacterium to efficiently transport lactose into the cell and metabolize it.