BIOC13H3 Lecture Notes - Lecture 11: Malonyl-Coa, Atp Citrate Lyase, Palmitoyl-Coa
Document Summary
Bioc13winter2013 lecture 11: fa biosynthesis, cholesterol and eicosanoid metabolism. Fatty acid synthase: ks = b-ketoacyl-acp synthase, mat = malonyl/acetyl-coa-acp transacylase, dh = b-hydroxyacyl-acp dehydrase, er = enoyl-acp reductase, kr = b-ketoacyl-acp reductase, te = palmitoyl thioesterase. Symptoms include skin rash, hair loss (alopecia), disturbance in sleeping patterns, poor night vision, sensitivity to bright light etc: rare because of widespread availability and use of appropriate supplements. Cholesterol: large hydrophobic molecule, controls membrane fluidity in eukaryotes, metabolic precursor to steroid hormones, the majority of serum-derived cholesterol comes from de novo biosynthesis in the liver, not from dietary cholesterol. Therefore, understanding cholesterol biosynthesis in relation to cardiovascular disease has been a very active research area: radioisotope labeling experiments have shown that all 27 carbon atoms of cholesterol are derived from acetyl-coa. Inactivation by phosphorylation by c-amp dependent kinases (pka: degradataion half life is 3 hours, gene expression is controlled by cholesterol levels.
