Biochemistry Exam 3 questions

Card Set Information

Author:
rwh824
ID:
112512
Filename:
Biochemistry Exam 3 questions
Updated:
2011-10-27 01:13:18
Tags:
Biochemistry
Folders:

Description:
biochemistry exam 3
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user rwh824 on FreezingBlue Flashcards. What would you like to do?


  1. a.
    Aerobic breakdown of glucose by the glycolytic pathway in muscles
    results in 2 molecules of pyruvate.
    b. Aerobic breakdown of glucose by the
    glycolytic pathway in RBCs results in 2 molecules of pyruvate.

    A. A = B
    B. A > B
    C. A < B
    B. A > B
    (this multiple choice question has been scrambled)
  2. Which one of the following conversions in
    glycolysis leads to the most direct production of ATP by substrate-level
    phosphorylation?

    a. 3
    phosphoglycerate to phosphoenolpyruvate
    b. glyceraldehyde 3 phosphate to 3 phosphoglycerate
    c. dihydroxyacetone phosphate to
    glyceraldehydes 3 – phosphate
    d. glucose to fructose 1 , 6 bisphophate
    e. pyruvate to lactate
    b. glyceraldehyde 3 phosphate to 3 phosphoglycerate
  3. In
    alcohol fermentation, the decarboxylation of pyruvate requires a coenzyme that
    contains the vitamin ..........
    thiamine
  4. What is substrate level phosphorylation?

    a.
    Phosphorylation of AMP by ATP
    b. ATP synthesis when the phosphate donor is a substrate
    with high phosphoryl transfer potential.
    c. Phosphorylation of glycolytic
    intermediates
    d. Phosphorylation of ATP coupled to an
    ion gradient
    e. ATP and AMP synthesis from 2
    molecules of ADP
    b. ATP synthesis when the phosphate donor is a substrate with high phosphoryl transfer potential
  5. The synthesis of glucose from pyruvate by
    gluconeogenesis:

    a.
    involves lactate as an intermediate
    b. Occurs in muscle (no, occurs in
    liver)
    c. Is stimulated by insulin
    d. Is inhibited by elevated levels of
    acetyl coA
    e. requires the participation of biotin
    e. requires the participation of biotin
  6. Which one of the followng reactions is unique
    to gluconeogenesis (not found in glycolysis)?

    a.
    lactate to pyruvate
    b. glucose 6 phosphate to fructose 6
    phosphate
    c. 3-phosphoglyceride to
    phosphoenolpyruvate
    d. pyruvate to oxaloacetate
    e. phosphoenolpyruvate to pyruvate
    d. pryuvate to oxaloacetate
  7. Which of the following vitamins or coenzymes
    does NOT participate in the oxidative decarboxylation of pyruvate?

    a.
    Lipoic Acid
    b. Thiamin
    c. Biotin
    d. Niacin
    e. Riboflavin
    c. Biotin
  8. What enzyme is responsible for the folowing
    reaction?
    Pyruvate + CoA + NAD+ to acetyl CoA + NADH + H⁺ + CO₂

    a.
    Acetyl CoA Synthetase
    b. Pyruvate Dehydrogenase
    c. Pyruvate Carboxylase
    d. Lactase Dehydrogenase
    e. Pyruvate Synthase
    b. Pyruvate Dehydrogenase
  9. Which one of the following conditions DECREASES
    the oxidation of acetyl CoA by the TCA cycle?

    a. a low
    ATP/ADP ratio
    b. a low NADH concentration due to rapid oxidation to NAD⁺
    through the respiratory chain
    c. a low NAD⁺/NADH ratio
    d. a high concentration of AMP
    e. a low GTP/GDP ratio
    c. a low NAD+/NADH ratio
  10. A 1-month-old baby showed abnormalities of the
    nervous system and increased lactic acid in the blood. The total amount of pyruvate dehydrogenase and
    α-ketogluterate were normal, but the total enzyme activity was reduced for
    both. Which ONE of the following
    statements concerning this baby is true?

    a. A diet
    containing high carbohydrate would be very beneficial
    b. The patient appears to have a thiamin deficiency
    c. Administering insulin would benefit
    this baby
    d. Exposing the baby to high oxygen
    levels would help
    e. TCA cycle would be accumulatingexcess
    succinyl coA
    b. The patient appears to have a thiamin deficiency
  11. This
    Citric Acid Cycle enzyme is also part of an electron-transport complex ............. .
    succinate dehydrogenase
  12. Choose the correct path taken by a pair of
    electrons as they travel down the Electron Transport chain.

    a. NADH
    + H⁺ to Complex I to Co-Q to
    Complex III to Site C to Complex IV to O₂
    b. FADH₂ to Complex I to
    Co-Q to Complex III to Site C to
    Complex IV to O₂
    c. NADH to Complex I to
    Complex II to Complex III to Site C to
    Complex IV to O₂
    d. FADH₂ to Complex II to
    Co-Q to
    Complex III to Site C to
    Complex IV to O₂
    e. Both A and D
    f. Both A and B
    e. Both A and D
  13. During oxidative phophorylation, which one of
    the following reduces O₂ to H₂O?

    a.
    Q-cytochrome C reductase
    b. ATPsynthase
    c. TCA cycle
    d. cytochrome C oxidase
    e. glycerol-3-P dehydrogenase
    d. cytochrome C oxidase
  14. The enzyme complexes associated with oxidative phosphorylation
    and the electron transport chain can be classified as _____________ proteins.

    A. both A and C
    B. lipid-anchored membrane
    C. water soluble
    D. peripheral membrane
    E. integral membrane
    E. integral membrane
    (this multiple choice question has been scrambled)
  15. Which of the following would exist in the most
    oxidized state in mitochondria treated with antimycin?

    a.
    FAD⁺/FADH₂
    b. NAD⁺/NADH₂
    c. NADH-Q reductase
    d. Succinate Q reductase
    e. Cytochrome oxidase
    e. Cytochrome oxidase
  16. Glycerol-3-phosphate
    dehydrogenase, the enzyme responsible for the glycerol phosphate shuttle,
    exists in two isoforms. The cytosolic enzyme uses (blank) as coenzyme, whereas the
    mitochondrial enzyme uses (blank) as the coenzyme.
    NAD⁺/NADH and FAD⁺/FADH₂
  17. Phosphorylase b, the inactive enzyme, can be
    allosterically activated.
    What physiological conditions renders phosphorylase b back to the inactive
    state
    (R to T state)?

    a. high
    ATP high AMP and glucose 6 phosphate levels
    b. high ATP and low calcium ion levels
    c. high ATP and glucose 6-phosphate levels
    d. high glucose
    e. all of the above
    c. high ATP and glucose 6-phosphate levels
  18. Calcium ion increase in the cytoplasm
    stimulates muscle contraction and therefore glycogenolysis. Calcium ion binds and leads to the activation
    of what enzyme in glycogen degradation?

    A. Phosphorylase kinase
    B. Protein kinase C
    C. Phosphorylase
    D. glycogen phosphorylase
    E. Phosphoglucomutase
    A. Phosphorylase kinase
    (this multiple choice question has been scrambled)
  19. Which statement is true abut the reaction
    catalyzed by glycogen synthase?

    a. It
    polymerizes free glucose to glycogen in the liver.
    b.. It requires UTP-glucose for chain lengthening.
    c. It can lengthen glycogen chains as
    well as form new branches.
    d. It requires a primer of four to eight linked glucose
    residues.
    e. It adds UDP-glucose to glycogenin
    through α 1,4 glycosidic linkages
    d. It requires a primer of four to eight linked glucose residues
  20. Glycogen phosphorylase is _________(more, less)
    active when phosphorylated, and it is __________ (activated, inhibited) by
    glucose 6-phosphate

    a. more;
    activated
    b. less; activated
    c. more; inhibited
    d. less; inhibited
    c. more; inhibited

What would you like to do?

Home > Flashcards > Print Preview