Factor: anything (living or non- living) that affects somthing else.
The factors affecting photosynthesis are:
• Carbon dioxide
• Temperature
• Light
Carbon dioxide
If carbon dioxide levels fall, the rate of photosynthesis will also fall. This is because there will be less of the gas to take part in the photosynthesis reactions. Likewise, if the carbon dioxide levels rise, the rate of photosynthesis will also rise. This is due to an increase in the gas available to take part in the photosynthesis reactions.
Temperature
All biological processes are controlled by proteins called enzymes. Enzymes need a particular temperature to work efficiently. If the temperature is too low, the enzymes slow down and so also does the rate of the reaction. Therefore low temperatures cause photosynthesis to slow down. On the other hand, if temperature goes too high, the enzymes may be destroyed and so the reaction will stop.
Light
Light provides the energy for the reactions to occur in photosynthesis. If the light intensity (strength of the light) is low, the rate of photosynthesis will be low due to the lack of energy. As light intensity increases, so too does the rate at which photosynthesis occurs. Remember that energy is needed for atoms to bond together. So, light energy is converted to chemical energy in food in the process of photosynthesis.