Why does NADH produce 3 ATP while QH2 and FADH2 only produce 2 ATP?

I learned in my biochemistry class that for every one molecule of NADH give rise to 3 ATP while QH2 (ubiquinol) and FADH2 only produce 2 ATP. Why is this? What process does each molecule have to go through to give rise to the ATP they yield? Thanks!

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  • Anonymous
    1 decade ago
    Favorite Answer

    NADH feeds its electrons into the electron transport chain at the beginning (Complex I). FADH2 feeds into the electron transport chain at Complex II (at a lower energy level down the chain). The high energy electrons from NADH have sufficient energy to result in 3 ATP whereas the lower energy electrons in FADH2 have only energy for 2 ATP.

    The donated electrons are passed along the electron transport chain from high energy level to low energy level (O2 is the final acceptor) via Complexes I - IV. As the energy is given up protons (H+) are pumped from the matrix of the mitochondria into the space between the inner and outer membranes of the mitochondria., thus establishing a H+ concentration gradient. The H+ then diffuse back through the ATP synthase in the inner membrane to the matrix resulting in ATP synthesis.

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  • 3 years ago

    Why Nadh Produce 3 Atp

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  • Ash
    Lv 4
    1 decade ago

    Look at the diagram (URL is given in the source.)

    When electron start from NADH to complex V, 3 ATPs are produced.

    When electron start from FADH2 (just after the NADH and before the first ATP formation), 2 ATPs are formed.

    Thus, 3 ATPs are formed in electron transport chain by one NADH. 2 ATPs are produced by the FADH2 because one ATP is already formed by the NADH (as shown in the figure)

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  • 4 years ago

    This Site Might Help You.

    RE:

    Why does NADH produce 3 ATP while QH2 and FADH2 only produce 2 ATP?

    I learned in my biochemistry class that for every one molecule of NADH give rise to 3 ATP while QH2 (ubiquinol) and FADH2 only produce 2 ATP. Why is this? What process does each molecule have to go through to give rise to the ATP they yield? Thanks!

    Source(s): nadh produce 3 atp qh2 fadh2 produce 2 atp: https://shortly.im/26AEJ
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