The main advantage of C4 and CAM plants are that they have
specially adapted metabolic pathway in order to limit exposure of Rubisco enzyme to oxygen (oxygen can inhibit Rubisco and reduce photosynthesis that way). Photorespiration is a process when Rubisco reacts with oxygen rather than with carbon dioxide. C4 plants and CAM plants tend
to minimize photorespiration. C4 plants separate steps of CO2 fixation and Calvin cycle in two different cell types. CAM plants separate these steps in time, between night and day.