On top of that, we can use these intermediates of the citric acid cycle to basically produce many different types of amino acids and bases and glucose molecules as well as other important groups used by the enzymes and proteins of Arabani. Now, what I'd like to focus on in this lecture briefly is the following idea. Because the citric acid cycle is so important, we have to make sure that the concentrations, the levels of these intermediate molecules is actually kept in check. So the concentration, the level of these molecules cannot actually drop below a certain value because if it does, the citric acid cycle will not actually take place. And so I'd like to focus on a specific type of process that allows us to actually regenerate and replenish the concentration of oxalo acetate, which in turn allows us to actually replenish the concentration of all these other intermediates. So remember, because this is a cyclic process, because we begin with oxyloacetate and then go back to that oxyloacetate, what that means is by replenishing the concentration of oxyloacetate, we in turn replenish the concentration of all the other intermediate molecules that are needed to produce all these different types of building blocks, as well as the NADH molecules which are needed to form ATP along the electron transport chain.