Photorespiration is when plants take in oxygen and light and release carbon dioxide. Contrary to photosynthesis. C3 plants have no system to minimize photorespiration, C4 plants minimize photoresperiation by separating the initial CO2 fixations and the Calvin cycle to be performed in different types of cells. CAM plants minimize photorespiration by taking CO2 by opening their stomata at night and then keeping the stomata closed during the day while they do photosynthesis.
