And so because the concentration of glucose is high, we do not need to synthesize the proteins, the enzymes that are involved in the breakdown of lactose. So once again, this takes place because at high concentration of glucose, the cell does not need to use lactose as the energy source because it has the glucose in the first place. And so the genes for our beta Galactosidase, as well as these other two genes, the proteins involved in the breakdown of lactose are essentially turned off. They are not expressed. Now, what exactly happens when the glucose concentration drops? So when the glucose concentration drops, our cyclic amp or cyclic adenosine monophosphate concentration will increase.