Now, to gain more intuition and understanding to what the opera is and how it actually works let's take a look at one particular example of the lack of an opera known as the Lac Operon which stands for the Lactose opera. This is the opera that is used by certain type of prokaryotic cell known as E. Coli. So prokaryotic cells basically control the genes by using the change in concentration of certain types of biological molecules. So prokaryotic cells have genes that respond to changes in concentration of certain types of biological molecules such as glucose. So basically when glucose concentration is high the glucose can basically or the cell can metabolize the glucose and use the ATP produced by the process of glycolysis to power the different types of processes that take place within our cell. However, what happens when the glucose concentration is low?