Essential Biochemistry - Biological Oxidation (Section 1)

  • 1
    Which of the following molecules is a product of the electron transport chain?
    Svare
    (C)
    ATP
  • 2
    Which molecule is directly involved in the transfer of electrons from FADH2 to the electron transport chain?
    Svare
    (B)
    Coenzyme Q
  • 3
    Which component of the ETC is associated with complex II?
    Svare
    (B)
    Succinate dehydrogenase
  • 4
    In energy currency of the cell is:
    Svare
    (A)
    High energy phosphate (~P)
  • 5
    Which of the following shuttles regenerates NAD+ in the cytosol, allowing glycolysis to continue under anaerobic conditions?
    Svare
    (B)
    Glycerol 3-phosphate shuttle
  • 6
    Which of the following is an example of substrate-level phosphorylation?
    Svare
    (C)
    The synthesis of ATP from ADP and Pi during glycolysis
  • 7
    What is the correct order of electron flow in the electron transport chain?
    Svare
    A
    B
  • 8
    What is the role of Complex IV (cytochrome c oxidase) in the electron transport chain?
    Svare
    (B)
    To reduce oxygen to water.
  • 9
    What happens to the energy released during electron transport?
    Svare
    (D)
    Both released as heat and used to pump protons.
  • 10
    What process is directly inhibited by cyanide?
    Svare
    (D)
    Complex IV
  • 11
    Which molecule is required as a terminal electron acceptor in the electron transport chain?
    Svare
    (C)
    Oxygen
  • 12
    What is the role of uncoupling proteins (UCPs)?
    Svare
    (C)
    To allow protons to bypass ATP synthase
  • 13
    What is the primary function of Complex III in the electron transport chain?
    Svare
    (D)
    To transfer electrons from CoQ to cytochrome c
  • 14
    What type of reaction does dehydrogenase catalyze?
    Svare
    (A)
    Oxidation
  • 15
    In oxidative phosphorylation, the oxidation of one molecule of NADH produces
    Svare
    (B)
    3 ATP molecules
  • 16
    What is the purpose of uncoupling agents like 2,4-dinitrophenol (DNP)?
    Svare
    (C)
    To allow protons to bypass ATP synthase and reduce ATP synthesis
  • 17
    The uncoupling of oxidative phosphorylation
    Svare
    (C)
    Inhibit ATP synthesis but not electron transport
  • 18
    Which complex in the electron transport chain pumps protons across the inner mitochondrial membrane?
    Svare
    A
    D
    C
  • 19
    What is the role of Coenzyme Q in the electron transport chain?
    Svare
    A
    B
    C
  • 20
    What is the role of the proton gradient in oxidative phosphorylation?
    Svare
    (C)
    To provide the energy for ATP synthesis
  • 21
    Which of the following is a mobile electron carrier in the electron transport chain?
    Svare
    A
    B
  • 22
    Which of the following molecules inhibits ATP synthase?
    Svare
    (C)
    Oligomycin
  • 23
    Which of the following statements is true regarding the role of Coenzyme Q (CoQ) in the electron transport chain?
    Svare
    (B)
    CoQ is a mobile carrier of electrons.
  • 24
    Which of the following is NOT a proton-pumping complex in the ETC?
    Svare
    (B)
    Complex II
  • 25
    Where does the electron transport chain occur in the mitochondria?
    Svare
    (B)
    The inner mitochondrial membrane
  • 26
    The flow of electrons through the electron transport chain results in:
    Svare
    (D)
    All of the above
  • 27
    Which of the following is a mobile carrier of electrons in the ETC?
    Svare
    (C)
    Cytochrome c
  • 28
    Which enzyme complex is responsible for synthesizing ATP?
    Svare
    (C)
    ATP synthase
  • 29
    Which of the following molecules donates electrons to the electron transport chain?
    Svare
    (C)
    NADH
  • 30
    Respiratory chain is found in:
    Svare
    (A)
    Mitochondria
  • 31
    The oxidation and phosphorylation of intact mitochondria is blocked by:
    Svare
    (D)
    All of them
  • 32
    In the malate-aspartate shuttle, what molecule is directly involved in transporting reducing equivalents across the inner mitochondrial membrane?
    Svare
    (A)
    Malate
  • 33
    In the chemiosmotic theory, what drives ATP synthesis?
    Svare
    (B)
    The proton gradient
  • 34
    What would be the expected result of a deficiency in cytochrome c?
    Svare
    (B)
    Impaired electron transport
  • 35
    Which complex directly oxidizes succinate?
    Svare
    (B)
    Complex II
  • 36
    What is the role of the inner mitochondrial membrane in oxidative phosphorylation?
    Svare
    (D)
    All of the above
  • 37
    Which of the following correctly represents the order of electron flow in the electron transport chain, starting with NADH?
    Svare
    (A)
    NADH -> Complex I -> CoQ -> Complex III -> Cytochrome c -> Complex IV -> O2
  • 38
    Which of the following is a characteristic of substrate-level phosphorylation?
    Svare
    (B)
    It directly produces ATP without the use of a proton gradient
  • 39
    What is the role of Complex II in the electron transport chain?
    Svare
    (A)
    To oxidize FADH2 and transfer electrons to CoQ
  • 40
    Enzyme that synthesizes ATP in oxidative phosphorylation is
    Svare
    (A)
    Reactase
  • 41
    Which one of the following respiratory chain components reacts directly with molecular oxygen?
    Svare
    (A)
    Cytochrome a3
  • 42
    Which of the following trace elements has role in ETC?
    Svare
    (D)
    Zinc
  • 43
    Which of the following molecules is directly reoxidized by complex IV?
    Svare
    (B)
    Cytochrome c
  • 44
    In oxidative phosphorylation, the oxidation of one molecule of FADH2 produces
    Svare
    (B)
    2 ATP molecules
  • 45
    What is the primary function of Coenzyme Q (Ubiquinone)?
    Svare
    (A)
    To transfer electrons from complex I to complex III
  • 46
    Which of the following shuttles is used to transport NADH equivalents across the inner mitochondrial membrane?
    Svare
    A
    B
  • 47
    Which complex in the electron transport chain does NOT pump protons?
    Svare
    (B)
    Complex II
  • 48
    Which of the following is the primary function of complex I?
    Svare
    (C)
    To pump protons and transfer electrons from NADH to CoQ
  • 49
    A biochemically substance that you act on as an uncoupler is:
    Svare
    (B)
    Free fatty acid
  • 50
    Which of the following is an inhibitor of the electron transport chain?
    Svare
    (B)
    Rotenone