So in step number five, this acetoacetal group is our reactant molecule. Now, this step number five is a reduction step. And the reductant molecule that we use is NADPH. So we use NADPH to basically transform this carbonyl group into an alcohol group and we form this molecule, as shown here, the enzyme domain on that FAS that I catalyze this step is known as beta keto acel ACP reductase. It's a reductase because it uses this reducing molecule to actually generate this alcohol from this carbonyl group. Now, we call it beta keto ACL because this is actually a beta keto molecule.