Our bodies love processing glucose, the primary energy source for many organisms. It is simple and easy to extract the energy contained within this simple sugar. But, there are other sugars that organisms can utilize such as lactose. One way that E. coli and many other bacteria harness lactose as an energy source is with the help of the lac operon. This episode explores the components of the lac operon and how the operon functions under varying levels of lactose and glucose.