What are the 3 main factors affecting the rate of photosynthesis?

Light - Increasing light intensity, increases the rate of photosynthesis up to a certain point. At this point, either temperature or CO₂ level is the limiting factor. CO₂ - Increasing CO₂ level, increases the rate of photosynthesis up to a certain point. At this point, either light intensity or temperature is the limiting factor. Temperature - Too low a temperature limits the rate of photosynthesis because the enzymes required for photosynthesis work more slowly at lower temperatures. Too high a temperature also limits the rate of photosynthesis because the enzymes become damaged (denatured). Therefore, there is an optimum temperature at which the enzymes are working effectively without becoming denatured.