Molecular oxygen is reduced to water by... ATP synthase(Complex V). succinate dehydrogenase (complex II). cytochrome c oxidase(Complex IV). glycerol-3-P dehydrogenase. Q-cytochrome c oxidoreductase(Complex III). the TCA cycle. QUESTION 27 The chemiosmotic hypothesis propeses that are used to create a gradient of that drives synthesis. electron carriers, electrons, glucose electrons, protons, ATP photons, protons, ATP protons, ADP. ATP protons, electrons, ATP.