Photosynthesis and cellular respiration are connected through an important relationship. This relationship enables life to survive as we know it. The products of one process are the reactants of the other. Note that the equation for cellular respiration is the direct opposite of photosynthesis:
cellular respiration: C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O
photosynthesis: 6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2
In both processes, energy is generated at the cellular level
Explanation:
Photosynthesis makes glucose that is used in cellular respiration to make ATP. Glucose is converted back to carbon dioxide, which is used in photosynthesis. While water breaks down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water. While photosynthesis requires carbon dioxide and releases oxygen, cellular respiration requires oxygen and releases carbon dioxide. It is the oxygen released that is used by us and other organisms for cellular respiration. We breathe that oxygen, which is transported through our blood to all our cells. In our cells, oxygen allows it to process cellular respiration. Cellular respiration works best in the presence of oxygen. Without oxygen, much less ATP would be produced.
Cellular respiration and photosynthesis are important parts of the carbon cycle. The carbon cycle is the path through which carbon is recycled in the biosphere. While cellular respiration releases carbon dioxide into the environment, photosynthesis takes carbon dioxide out of the atmosphere. The exchange of carbon dioxide and oxygen during photosynthesis (Figure below) and cellular respiration throughout the world help to maintain atmospheric levels of oxygen and carbon dioxide at a stable level.
