Lipid Metabolism I Dr Kevin Ahern 1 2
Lipid Metabolism I Dr. Kevin Ahern
1 2 3 Fat and Glycerophospholipid Synthesis 1 2 3
Fat (Triacylglycerol) Glycerol-3 -P Phosphatidic Acid Glycerophospholipids
Signaling Catalysis Fat Breakdown
Glycerophospholipids / Phosphatides Lipid Glycero Phospho
X X X
• • Glycerophospholipic Synthesis Involves CDPActivated Intermediate Two General Mechanisms Will Split Off as CMP Phosphatidyl Portion of Final Product Phosphatidic Acid + CTP + PPi CDP-Diacylglycerol
+ CM P CDP-Diacylglycerol + Inositol Phosphatidylinositol + CMP
CDP + CMP
• Second Mechanism - Activate Add-on Molecule Adds to Diacylglycerol AT P Ethanolamine AT P Splits Off CTP PPi Phosphorylethanolamine CDP-Ethanolamine
CDP-Ethanolamine + Diacylglycerol Phosphatidylethanolamine + CMP
1 1 2 2 3 3 1 3
Sphingolipid Biosynthesis Amino Acid Fatty Acid Branch Point Sphingolipids
Sphingolipid Synthesis Ceramide Synthesis
Membrane Lipid Metabolism • Sphingolipids R= Phosphocholine OR Sphingomyelin R= Phosphoethanolamine R= Single Sugar Cerebroside R= Complex Sugar Ganglioside
Sphingolipid Breakdown Diseases
Cholesterol Biosynthesis Cholesterol Acetyl Group
Cholesterol Biosynthesis Branch Point
30 Carbons Lanosterol 30 Carbons 15 Carbons 10 Carbons Squalene IPP 2 + DPP Farnesyl-PP Geranyl-PP IPP 5 Carbons Each DMAPP Acetyl-Co. A
19 Steps Lanosterol Cholesterol
Cholesterol Metabolism Excretion Cholesterol Bile Acids Mineralocorticoids & Corticosteroids
Cholesterol Metabolism
Lipid Movement From the Diet Inside Intestine Outside Intestine Reattachment of 2 Fatty Acids Removal of 2 Fatty Acids
Apolipoprotein Complexes
Chylomicron
Receptor-mediated Endocytosis
Foam Cell Aggregate
Carotid Artery Plaque
- Slides: 31