Acetyl Coa & Tca Cycle

14 Questions | Total Attempts: 218

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Acetyl Coa & Tca Cycle - Quiz

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Questions and Answers
  • 1. 
    Pyruvate dehydrogenase complex catalyzes the:
    • A. 

      Oxidative decarboxylation of pyruvate to CO2 and acetyl CoA

    • B. 

      Citrate to isocitrate reaction

    • C. 

      Addition of a carboxylic acid to pyruvate, forming oxaloacetate

    • D. 

      Formation of fumarate and FADH2 from succinate

  • 2. 
    1 mole of pyruvate to acetyl-CoA yields ___ mole(s) of NADH.
    • A. 

      1

    • B. 

      2

    • C. 

      4

    • D. 

      3

  • 3. 
    Which cofactors of the pyruvate dehydrogenase reaction are permanently bound?
    • A. 

      Thiamine pyrophosphate

    • B. 

      Lipoamide

    • C. 

      Flavin adenine dinucleotide

    • D. 

      Nicotinamide adenine dinucleotide

    • E. 

      Coenzyme A

  • 4. 
    Which pyruvate dehydrogenase cofactors are acyl group carriers?
    • A. 

      Coenzyme A

    • B. 

      Lipoamide

    • C. 

      FAD

    • D. 

      NAD+

    • E. 

      TPP

  • 5. 
    Molecules with ____, such as dihydrolipoamide, are targets for covalent modification by arsenite.
    • A. 

      Proximal thiols

    • B. 

      Distal thiols

    • C. 

      Proximal hydroxyls

    • D. 

      Distal hydroxyls

  • 6. 
    ______ is complex II of the mitochondrial electron transport chain.
    • A. 

      Succinate dehydrogenase

    • B. 

      Malate dehydrogenase

    • C. 

      α-ketoglutarate dehydrogenase

    • D. 

      Aconitase

  • 7. 
    ____ and _____ inhibit key steps of the TCA cycle.
    • A. 

      ATP; NADH

    • B. 

      NAD+; ADP

    • C. 

      Succinyl CoA; ADP

    • D. 

      ATP: NAD+

  • 8. 
    Which PRODUCTS are not formed when there is an excess of ATP and NADH?
    • A. 

      Acetyl CoA

    • B. 

      α-ketoglutarate

    • C. 

      Succinyl-CoA

    • D. 

      Isocitrate

    • E. 

      Pyruvate

  • 9. 
    Catabolic action yields:
    • A. 

      High energy metabolites

    • B. 

      New material (ie, amino acids, porphyrins)

  • 10. 
    The TCA cycle is considered to be anapleurotic. This describes:
    • A. 

      That there are multiple points around the cycle where reactants feed in.

    • B. 

      The circular, regenerative nature of the TCA cycle.

    • C. 

      That malate is the only TCA cycle product that can be shunted through the mitochondrial membrane.

    • D. 

      That the TCA cycle is reversible when needed.

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