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. So when the beta ketoaceel ACP reductase domain of ACP uses the reducing power of NADPH, we ultimately generate that D three hydroxybutyl molecule that we have here. So this is a reducing step. Let's move on to step number six.