Describe and explain the three main factors affecting the rate of photosynthesis

The rate of photosynthesis is affected by:

1. Light intensity - without enough light, cells cannot photosynthesize even if there is an excess of carbon dioxide and water

2. Carbon dioxide concentration - without enough carbon dioxide, cells cannot photosynthesize even if there is plenty of water and a suitable light intensity 

3. Temperature - plants cannot photosynthesize in high temperatures as the enzymes involved in the reaction cannot function/denature but in low temperatures the rate of reaction would be too slow to allow the reaction to take place