Biochem Final Review

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Biochem Final Review
2011-08-02 19:46:41

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  1. What is the purpose of bile salts? Where are they synthesized? Where are they secreted from?
    • To mix with intestinal lipids to make them water soluble
    • Synthesized in the Liver
    • Secreted from Gallbladder
  2. Where is lipase & phospholipaseA2 secreted from?
    Pancreas - these mix with bile salt / lipid mix to prepare them to be absorbed by Intestinal walls; this mix becomes triacylglycerols
  3. Where are chylomicrons found?
    • Small Intestine - they are the "foamy part of detergent"
    • Chylomicrons are also known as apolipoproteins
  4. Once apolipoproteins are made, where do they go?
    • Into the Lymph System where it travels to other parts of the body as storage or to create energy through oxidation
    • The release through the Lymph System limits the rate this material is released into the blood (a protection system)
  5. What is the function of lipoproteins?
    They transport fat and cholesterol in the blood
  6. What determines the whether lipoprotiens are called HDL / LDL / etc?
    • The protein density
    • HDL's have high protein density
    • LDL's have low protein density
  7. Chylomicrons are majors carriers of what?
  8. What is the difference between cholesterol and cholesterol esters?
    Cholesterol esters are more hydrophobic (non water soluble)
  9. What transports ingested fat from intestinal walls to adipose and liver?
  10. Where is VLDL made? What is its purpose?
    • VLDL is made in the Liver
    • Its function is to transport fat to other tissues (such as adipocytes)
  11. Which lipoprotein contains the major source of cholesterol?
  12. What does cholesterol used for?
    • Making cell membranes, cortisol, testosterone, estrogen, aldosterone, etc
    • LDL's are only considered "bad" in large quantities which lead to atherosclerosis (hardening of vessels and build-up of obstruction in the vessels leading to heart disease and stroke
  13. What is the purpose of HDL's? Where is it produced?
    • Transport / gather cholesterol from peripheral tissue back to the Liver where it is used and excreted as bile
    • It is produced by the Liver and enterocytes
  14. If you have a genetic disorder or enzyme disorder, what are these disorders due to?
    Protein disorder
  15. What is the difference between acquired hyperlipoproteinemia and and genetic hyperlipoproteinemia?
    • Acquired - non familial
    • Genetic - familial
  16. What is the pathway of Triglycerides?
    Acyl CoA
  17. What is the pathway of Cholesterol?
    Acetyl CoA
  18. What inhibits HMG-CoA reductase?
  19. What is the central intermediate in lipid metabolism?
    Acetyl CoA
  20. What is the most dominate protein the the blood stream?
    Albumins - it is also a water soluble protein that transports fatty acids
  21. This is the key enzyme for causing fatty acid release from adipocytes?
    Hormone-sensitive Lipase
  22. This transports fatty acids into the mitochondria during the breakdown of lipids for the generation of metabolic energy
    Carnitine (like a boat)
  23. This enzyme stimulates reverse cholesterol transport from tissues that have excessive amounts of cholesterol into HDL molecules.
    Lecithin-cholesterol acyl transferase (LCAT)
  24. What is this condition called when you have an increase in lipoproteins concentration in the blood?
  25. What is this condition when you have large amounts of chylomicrons and triglycerides in the the plasma for a normal diet?
    Hyperlipoproteinemia Type I
  26. What condition is this when one has increased plasma levels of β-lipoproteins and cholesterol as well as elevated LDL but normal triglycerides?
    Hyperlipoproteinemia Type IIA
  27. What condition is this when one has increased plasma levels of β-lipoproteins and cholesterol as well as elevated LDL, cholesterol and triglycerides?
    Hyperlipoproteinemia Type IIB
  28. What is the difference between Homozygous and Heterozygous Hyperlipoproteinemia?
    • Homzygous - severe lipid changes, with manifestations on the body (xanthomatosis, xanthelesma, corneal arcus, atherosclerosis)
    • Heterozygous - mild lipid changes
  29. The process of removing amine groups from molecules due to excess protein intake
  30. The process of muscle cells using amino acids as an energy source while eliminating nitrogen
    Glucose / Alanine Cycle
  31. What is the purpose of the Alanine Cycle?
    • Shuttle to Liver to make glucose
    • Recycles carbon skeletons to between Muscle and Liver
    • Transports NH4+ to Liver and is converted to urea (where expelled)
  32. A sequence of DNA that has been altered or mutated from its original form
  33. Responsible for normal cell growth and proliferation. However, subtle changes can alter their ability to function normally thereby activating their cancer-causing potential
  34. What is the name of the group of enzymes invovled in the detoxification process of Phase I?
    Cytochrome P450 family
  35. What does Phase II detoxification typically involve to neutralize toxins and reactivate intermediates left over from Phase I?
    Biochemical conjugation
  36. A significant pathway in the Phase II detoxification mechanism. It combines glucuronic acid with toxins.
  37. This is excreted from bile. It is responsible for the yellow color of bruises and yellow discoloration in jaundice.
  38. When RBC's get old or damages, what system gets rid of them?
  39. Is unconjugated bilirubin water soluble?
    No - it is bound to albumin and sent to the liver where it gets conjugated
  40. Unconjugated hyperbilirubinemia can lead to accumulation of bilirubin in certain brain regions in new-born babies is know as?
  41. Period when ingested nutrients are entering the blood from the GI tract
    Absorptive State
  42. Period when the GI Tract is empty of nutrients and energy must be supplied from the stores in the body
    Postabsorptive State
  43. Going without food for 24 hours
  44. The catabolism of triaclglycerols yields glycerol and fatty acids. This occurs mainly in adipose tissue and the released glycerol is converted into glucose in the liver.
  45. The utilization of fat instead of glucose
    Glucose Sparing