So in the case of d three hydroxybutyrate, that is transformed back into acetyl acetate by the activity of this enzyme. But now we use an NAD plus to form NADH, which is the opposite of this step here. If we have aceto acetate going into the target cell, that simply enters directly in this stage, and the acetyl acetate is transformed into acetoacy acetoacetal coenzyme A, and that is catalyzed by the enzyme COA transferase. And so this requires succinct coenzyme a. So you form succinate and acetoacetal coenzyme A. And then this acetyl coenzyme A reacts with a coenzyme a molecule and is catalyzed by thylase to form two acetyl coenzyme a molecules, which then can be used to generate these energy molecules.