What “ingredient” is part of photosynthesis, but not part of the chemical equation?

Carbon, hydrogen, and oxygen are the chemical ingredients necessary for photosynthesis to take place. Hydrogen and oxygen both come from the water in the hydrosphere. Carbon and oxygen come from the carbon dioxide that animals and humans breathe into the atmosphere. Although it is not a chemical ingredient, without energy from the sun, none of this process could occur. (hope it helps-

Explanation:

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.