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How many protons pumped per molecule of PQH2 reduced by cyt bf via q cycle? watch

    • Thread Starter

    In my lectures I was told 2 protons pumped per molecule of PQH2 reduced to PQ.
    However, in my textbook (stryer), it explains that 1 molecule of PQH2 transfers 2 e- to 2 PC, one at a time, to form 1 molecule of PQ and 2 molecule of reduced PC. The 2 protons flow into the thylakoid space.
    Then, 1 molecule of PQ is reduced to PQH2 with protons from the stroma. The PQH2 is reoxidised to form PQ and the 2 protons flow into thyakoid space.

    Therefore, in total, 4 protons are pumped into the thylakoid space/ PQH2. As there are 2 molecules of PQH2 formed by the oxidation of 2 molecules of water, 8 protons ought to be pumped in total. This is as the textbook explains, contrary to what my lecturer says who hasn't given an explanation as to why it's 2.

    Any help? Thanks

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