In addition to those seven catalytic sites, we also have a domain we call the Acyl carrier protein domain. And that's shown in green. And attached onto this ACL carrier protein, is the vitamin B five derivative we call phosphopancythione. Now, on the tip of this phosphopancythine is a sulfide hydro group. And attached onto this sulfidel group is the next acetolico enzyme, a molecule that will be used to actually elongate that fatty acid chain. So we see that fatty acid synthesis incorporates carbon atoms from acetylco enzyme A molecules onto that growing fatty acid chain.