Lecture4.pdf

Lecture 4 Synthesis of Triacylglycerols and Phospholipids Chapter 21 Sources of L-Glycerol 3-Phosphate Synthesis of Phosphatidic Acid Phosphatidic Acid: Parent of Triglycerides and Phospholipids Triglycerides Turn Over Rapidly Adipocyte Metabolism and Type II (Adult Onset) Diabetes -High FFA in blood reduces insulin sensitivity -Blood FFA is reduced when FFA in adipocytes get re-esterified -Re-esterification requires glycerol-P -Adipocytes normally lack glycerol kinase -Thiazoladinediones stimulate TG synthesis in adipocytes, lowering blood FFA Glyceroneogenesis in Adipocytes (Adipocytes Lack Glycerol Kinase) Natural and Synthetic Glucocorticoids Triglycerides Cycle Betwen Liver and Adipose Tissue Thiazolidinediones Reduce Blood FFA Thiazolidinediones Induce Key Enzyme in Glyceroneogenesis, Lowering FFA Phospholipid Synthesis Phospholipids: Phosphodiesters Activation of Lipid Precursors with CDP Synthesis of Phosphatidylglycerol and Phosphatidylserine Phosphatidylglycerol and Phosphatidylethanolamine PE by Head-Group Exchange or Decarboxylation of PS PC by Methylation of PE S-Adenosyl-methionine (SAM) PC by Choline Salvage Path Sphingolipid Biosynthesis Sphingolipid Biosynthesis Sphingolipid Biosynthesis Sphingolipid Biosynthesis Sphingolipid Biosynthesis Unsolved Problems in Phospholipid Synthesis -Regulation of total phospholipid -Control of polar head-group ratios -Regulation of faty acid composition -Saturated vs. unsaturated -Chain length -Position on glycerol -Targeting to intracelular membranes -Turnover Dave Nelson 508_L4_2010.ppt