Now, the enzyme that catalyzes steps one through step seven is fatty acid syntax. And remember that fatty acid synthase or simply SAS is a single polypeptide chain that actually contains seven different catalytic sites, seven different catalytic domains, as well as an ACP domain. And the ACP domain stands for Acyl carrier protein. Remember, the Acyl carrier protein actually contains a phosphate group and that group contains this sulf hydro group. And that will allow the binding of certain molecules as we'll see in just a moment. So this is our FAS and we have this ACP that contains the phosphate that is not shown, that contains this sulf Hydrol group and that will bind this molecule, the CETO coenzyme A as we'll see in just a moment.