Biochem test 4

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Biochem test 4
2011-11-12 14:50:35
Biochem test

Biochem test 4
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  1. The purpose of the pentose phosphate pathway is to?
    A) b and c
    B) synthesize 5-carbon sugars
    C) a and b
    D) generate NADPH
    E) generate ATP
    A) b and c
    (this multiple choice question has been scrambled)
  2. Hemolytic anemia is a result of increase in reactive oxygen species. The manifestation of the disease is actually caused by a defect in..................
    glucose 6-phosphate dehydrogenase
  3. The hormone.............induces lipolysis, whereas the hormone..............inhibits the process.
    glucagon; epinephrine
  4. Three rounds of beta-oxidation of palmitate results in ................
    complete oxidation of palmitate
  5. The carbon atoms from a fatty acid with an odd number of carbons will enter the citric acid cycle as acetyl-CoA and.................
  6. Ketone bodies are formed in the liver and transported to the extrahepatic tissues mainly as...............
  7. The elongation of gatty acids during fatty acid synthesis is a repetition of three reactions adding carbons from.............after each cycle until completion.
    acetyl CoA
  8. Which of the following is not required in the synthesis of fatty acids?
    a) acetyl-CoA
    b) biotin
    c) HCO3- (CO2)
    d) malonyl-CoA
    e) NADH
  9. Prostaglandins and thromboxanes are synthesized from................, a 20-carbon fatty acid.
    arachadonic acid
  10. How are fatty acids longer than 16 carbons formed?
    a) by elongation reactions catalyzed by enzymes on the endoplasmic reticulum
    b) by one-carbon additions at the mitochondrial membrane
    c) by elongation reactions catalyzed by enzymes in the liver
    d) all of the above
    e) none
  11. Which of the following statements about the structure of cholesterol is true?
    a) it contatins 27 carbon atoms
    b) it contains only H, O, C, and N
    c) it is completely saturated
    d) it contains four hexane rings fused together
    e) only part of the carbons are derived from isoprene units
  12. Which of the following is the biologically active form of vitamin D?
    1, 25-dihydroxycholecalciferol
  13. A patient is found to have a high concentration of cholesterol in the blood and deopsists of cholesterol under the skin. the patient is diagnosed with familial hypercholesterolemia. What is the likely cause of this condition?
    insufficient chylomicron concentration in the blood
  14. What are the steps of cholesterol synthesis?
    • 1. Biosynthesis of Mevalonate from Acetyl CoA (2)
    • 2. Formation of Iosprenoid units from Mevalonate
    • 3. Six Isoprenoid units form squalene (30-C)
    • 4. Squalene cyclized to Lanosterol
    • 5. Lanesterol converted to cholesterol
  15. Which do you expect to have the highest protein content by percent?
  16. Glutamate is the precursor for amino acids glutamine, proline, and .....................
  17. This amino acid, in high levels, is correlated with the damage of cells lining the blodd vessels.
  18. In the transamination reaction shown below, which of the following are the products X and Y?
    • oxaloactate to aspartate
    • glutamate to alph-ketoglutarate
  19. A female neonate did well until approximately 24 hrs of age when she became lethargic. Analysis of her blood revealed a drastic elevation of argininosuccinate. Which of the following enzymatic activities is most likely to be deficient in this patient?
  20. A ribose sugar is added to.................rings after their synthesis and to................rings during their synthesis.
    pyrimidine, purine
  21. Which is a common precurso in the de novo synthesis of purine nucleotides?
    inosine 5'-monophosphate
  22. What is histidine derived from?
  23. What is the purpose of the PPP in red blood cells?
    produce NADPH to regenerate glutahtione
  24. How many ATP can be produced from a 14-carbon molecule?
  25. How many ATP are produced per round of beta-oxidation?
  26. What enzyme cleaves fatty acids from acyl carrier proteins?
  27. What enzymes introduce double bonds beyond the 9th carbon?
    desaturases. not found in human systems
  28. Where does beta-oxidation occur?
  29. What form do fatty acids enter the mitochondria as?
  30. What are the step of beta-oxidation?
    oxidize, hydrate, oxidize, thiolysis
  31. What enzyme is needed for fatty acided monounsaturated?
    enoyl-CoA isomerase
  32. What is vitamin B12 also known as?
  33. What reaction is vitamin B12 for needed as a cofactor?
    mehtylmalonyl-CoA to succinyl-CoA