So, once again, within the matrix of the mitochondria, the z three hydroxybutyrate dehydrogenase enzyme can reduce the acetoacetate into another ketone body known as z three hydroxybutyrate. And the equilibrium of these two molecules basically is determined by the ratio of NADH to NAD plus within the matrix of the mitochondria. Now, the other reaction that can take place is the spontaneous decarboxylation of the acetone acetate to this nonmetabolizable form, the acetone, which can be released via the breathing process. Now, when do we produce ketone bodies? Well, actually, our liver produces small amounts of ketone bodies normally. Why?