Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle. View Available Hint(s) Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle. consumed...consumed oxidized...reduced consumed...reduced reduced...oxidized reduced...reduced