lecture 39.txt

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lecture 39.txt
2010-10-22 23:33:27

Important stuff from lecture 39: Lipoprotein metabolism
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  1. What is the main purpose of lipoproteins?
    to transport lipids and fat-soluble vitamins in the blood
  2. What is the structural protein for chylomicrons and chylomicron remnants?
    Apo B-48, made in the intestine
  3. What is the activator of lipoprotein lipase?
    Apo C-II ("borrowed from HDL)
  4. What are the two functions of Apo B-100?
    • Structural component of VLDL, IDL, and LDL
    • Ligand for LDL receptor
  5. What are the two functions of Apo A-I?
    • Structural component of HDL
    • Activator of PCAT enzyme
  6. What is the function of Apo E?
    • Ligand for hepatic Apo E receptor for CM remnants clearing
    • Ligand for Apo E receptor for IDL clearing
  7. What receptor in the liver binds to the chylomicron remnant?
    Apo E receptor
  8. What receptor in extrahepatic tissue and the liver binds to LDL?
    Apo B-100 receptor
  9. What do bile acid resins (like cholestyramin) do to the absorption of bile salts?
    Prevents the re-absorption of bile salts and forces the liver to use more cholesterol for bile salt synthesis.
  10. What two effects will the decrease in cytosolic cholesterol result in?
    • Increase in LDL receptor expression (decrease in serum cholesterol)
    • Increase in HMG-CoA reductase expression (increase in de novo synthesis of cholesterol)
  11. What are the three main functions of HDL?
    • Resevoir for apolipoproteins (Apo C-II and Apo E)
    • HDL uptake of unesterified cholesterol
    • Esterification of cholesterol (by PCAT)
  12. What is the function of CETP?
    moves CEs from HDL to VLDL in exchange for TG
  13. Where does HDL get its cholesterol?
    • Peripheral cells
    • Macrophages (foam cells) --> antiatherogenic