The overall effect of photosynthesis is to increase the concentration of oxygen in the Earth's atmosphere. This stage also requires energy, which is supplied by the ATP made by the light reactions.

This process, called photosynthesis, is essential to the global carbon cycle and organisms that conduct photosynthesis represent the lowest level in most food chains (Figure 1). Most living things ...

A similar method described on the previous page can be used to prove that photosynthesis doesn ... variable – the presence or absence of light. Dependent variable – whether starch is present ...