BIOLCHEM 415 Lecture 25: Exam #3 Notes - Lecture 25-36

• School: U of M
• Department: Biological Chemistry
• Course: BIOLCHEM 415
• Professor: Raymond Trievel

Document Summary

Integration of pathways: glycolysis, triacylglycerol synthesis and breakdown, phospholipid synthesis. Three classes of membrane lipids: phospholipids (glycerophospholipids) = fatty acid + glycerol backbone + alcohol, ex. Phosphatidylcholine: sphingolipids (glycolipids) = fatty acid + sphingosine backbone + sugar unit (glucose or galactose, ex. Glycerophospholipid synthesis: requires activation of either partner (phosphatidate or alcohol) Sphingolipids: sphingosine (not glycerol) backbone, two classes, sphingophospholipids and (sphingo)glycolipids, sphingolipids, sphingosine backbone, fatty acid, a phosphodiester, an alcohol, glycolipids, sphingosine backbone, fatty acid, sugar unit(s, cerebroside, ganglioside. Sphingolipids are synthesized via ceramide: w/+1 sialic acid, two branches from ceramide: sphingomyelin and cerebroside. Cholesterol synthesis: simple building blocks, complex reactions: multi-stage synthetic process, 1. Conversion of acetyl coa to mevalonate: mevalonate = rate limiting/committed step, 2. Synthesis of isopentenyl pyrophosphate, an activated isoprene unit: 3. Condensation of six molecules of isopentenyl pyrophosphate to squalene: 4. Squalene cyclizes and is converted to cholesterol (19 steps)