It's a disaccharide that consists of two individual sugar monomers. So our lactose consists of a glucose as well as a galactose. Now, the enzyme that actually catalyzes the breakdown of lactose into glucose is known as betagalactosidase and betagalactosidase is basically controlled. So the synthesis of the protein, the enzyme beta Galacticidase is controlled by a special type of operon found on the DNA of the prokaryotic cell known as the lac operon. So let's take a look at the lac opera. The lac opera is basically this section here.