What are the internal factors which affects photosynthesis?

Internal factors which affects photosynthesis are as follows: 

1. Chlorophyll: 

a. Though presence of chlorophyll is essential for photosynthesis but rate of photosynthesis is proportional to the quantity of chlorophyll present.

b. It is because of the fact that chlorophyll merely acts as a biocatalyst and hence a small quantity is quite enough to maintain the large bulk of the reacting substances. 

2. Sugar: 

The final product in the photosynthesis reaction is sugar and its accumulation in the cells slow down the process of photosynthesis. 

3. Internal structures: 

The thickness of cuticle and epidermis of the leaf, the size and distribution of intercellular spaces and the distribution of the stomata and the development of chlorenchyma and other tissues also affects the rate of photosynthesis.