So, in the next several lectures, we're going to look at the details of this complicated process. But in this lecture, what I'd like to focus in is on seven important facts that you have to know about fatty acid synthesis. So, fact number one, fatty acid synthesis takes place in the cytoplasm, and this is in contrast to the beta oxidation, the breakdown of fatty acids which takes place in the matrix of the mitochondria. Fact number two in eukaryotic cells to cells in our own body, we actually have a single polypeptide chain, a single protein known as fatty acid synthase that catalyzes the elongation, the formation of fatty acid molecules. And this fatty acid synthase actually contains seven different catalytic sites, which each carries out its own specific function, as we'll see in the next lecture. Now, in addition to these seven catalytic sites on the fatty acid synthase, we also have a domain we call the Acyl carrier protein domain, or ACP domain.