Electron Transport Chain Practice Exam Questions With Answers

30 Questions | Total Attempts: 420

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Electron Transport Chain Practice Exam Questions With Answers - Quiz

Take this Electron Transport Chain (ETC) practice exam questions with answers quiz and evaluate for yourself. An ETC is a series of four protein complexes (and/or other molecules) that couple redox reactions and transfer electrons from electron donors to electron acceptors. Here, in this quiz, you'll be asked questions related to the citric acid cycle, enzymes involved in this, and the products formed during the cycle. If you know about these processes, why don't you play the quiz? Good luck!


Questions and Answers
  • 1. 
    A reaction has a positive delta G. This means...
    • A. 

      It is endergonic

    • B. 

      It is exergonic

    • C. 

      It is endothermic

    • D. 

      It is exothermic

  • 2. 
    Which is the correct Gibbs free energy equation?
    • A. 

      ΔG = ΔT - S*ΔH

    • B. 

      ΔG = ΔH + T*ΔS

    • C. 

      ΔG = ΔH - T*ΔS

    • D. 

      None of the above

  • 3. 
    A reaction needs some energy put into it in order to start. The reaction is...
    • A. 

      Endergonic

    • B. 

      Exergonic

    • C. 

      Endothermic

    • D. 

      Not enough information

  • 4. 
    Enzymes...
    • A. 

      Supply activation energy, making the reaction more likely to occur

    • B. 

      Are reactants in endergonic reactions

    • C. 

      Stabilize the transition state

    • D. 

      Are a type of catalytic substrate

  • 5. 
    What is allosteric inhibition?
    • A. 

      The enzyme is withdrawn into the cytoplasm

    • B. 

      A protein binds to another active site, affecting the first active site

    • C. 

      A molecule binds to and blocks the active site

    • D. 

      None of the above

  • 6. 
    An enzyme can have multiple ____________.
    • A. 

      Active sites

    • B. 

      Reacting sites

    • C. 

      Losing sites

    • D. 

      None of the above

  • 7. 
    How many NADH molecules are made in glycolysis?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 8. 
    The acetyl group is extracted from pyruvate, releasing:
    • A. 

      ATP and H2O

    • B. 

      ATP and CO2

    • C. 

      NADH and CO2

    • D. 

      NADH and H2O

  • 9. 
    Which citric acid cycle stages converts NAD+ to NADH+H+? Select all that apply.
    • A. 

      Citrate→isocitrate

    • B. 

      Isocitrate→α-ketoglutarate

    • C. 

      α-ketoglutarate→succinyl CoA

    • D. 

      Succinyl CoA→succinate

    • E. 

      Succinate→fumarate

    • F. 

      Fumarate→malate

    • G. 

      Malate→oxaloacetate

  • 10. 
    Succinyl CoA is converted to succinate, directly doing which of the following?
    • A. 

      ADP to ATP

    • B. 

      Releases H2O

    • C. 

      FAD to FADH2

    • D. 

      GDP to GTP

  • 11. 
    How many net molecules of ATP are made in glycolysis?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 12. 
    Where does glycolysis occur?
    • A. 

      Cytoplasm

    • B. 

      Mitochondria

    • C. 

      Golgi apparatus

    • D. 

      GLUT receptors

  • 13. 
    What is the last carrier in the electron transport chain?
    • A. 

      GTP

    • B. 

      H+

    • C. 

      NADH

    • D. 

      O2

  • 14. 
    Which way does the electron transport chain pump H ions?
    • A. 

      Against the concentration gradient: from the inner membrane space to the matrix

    • B. 

      Down the concentration gradient: from the inner membrane space to the matrix

    • C. 

      Against the concentration gradient: from the matrix to the inner membrane space

    • D. 

      Down the concentration gradient: from the matrix to the inner membrane space

  • 15. 
    Which complex is also involved in the citric acid cycle (succinate dehydrogenase)?
    • A. 

      Complex I

    • B. 

      Complex II

    • C. 

      Complex III

    • D. 

      Complex IV

  • 16. 
    How many alpha subunits are in the F1 portion of ATP synthase?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 17. 
    H+ ions cause the gamma rod in ATP synthase to rotate, triggering a conformational change in alpha subunits that catalyze a reaction between ADP and inorganic phosphate
    • A. 

      True

    • B. 

      False

  • 18. 
    About how many H+ are needed to make 1 ATP?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 19. 
    Per glucose molecule, how many NADH are produced? Account for glycolysis, pyruvate oxidation, and the citric acid cycle.
    • A. 

      8

    • B. 

      10

    • C. 

      11

    • D. 

      12

  • 20. 
    Which electron carrier moves from complex III to complex IV?
    • A. 

      Flavin

    • B. 

      Ubiquinone

    • C. 

      Iron sulfur cluster

    • D. 

      Cytochrome C

  • 21. 
    Which route does an electron from NADH take in the ETC?
    • A. 

      Complex II, ubiquinone, complex III, complex IV

    • B. 

      Complex I, ubiquinone, complex III, complex IV

    • C. 

      Complex I, complex II, cytochrome C, complex IV

    • D. 

      Complex II, ubiquinone, cytochrome C, complex IV

  • 22. 
    What is the actual yield of ATP per NADH?
    • A. 

      3

    • B. 

      2.5

    • C. 

      2

    • D. 

      1.5

  • 23. 
    Which of the following are true of fermentation? Select all that apply.
    • A. 

      It occurs in the presence of oxygen.

    • B. 

      One of the products can be lactic acid

    • C. 

      CO2 can be released

    • D. 

      It converts NADH to NAD+

  • 24. 
    How are amino acids integrated into the catabolic pathways?
    • A. 

      Their nitrogen is removed, converting them into components of the CAC.

    • B. 

      Their carbon is removed, releasing energy.

    • C. 

      They are oxidized by pyruvate and join the CAC.

    • D. 

      Amino acids are products of anabolic reactions, never part of the catabolic pathway.

  • 25. 
    Where does photosynthesis get its electrons from initially?
    • A. 

      NADH

    • B. 

      CO2

    • C. 

      FADH2

    • D. 

      H2O

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