What is the opposite of photosynthesis?

The opposite of photosynthesis is cellular respiration. While photosynthesis involves the absorption of carbon dioxide and release of oxygen, cellular respiration involves the absorption of oxygen and release of carbon dioxide. During this process, cells break down glucose molecules to produce energy ATP, which can be used for various cellular processes. This process occurs in the mitochondria of the cells. Unlike photosynthesis, which occurs only in green plants, cellular respiration is a process that occurs in all living organisms, including plants, animals, and microorganisms.