Final answer:
Both photosynthesis and cellular respiration involve the exchange of carbon and serve as reciprocal processes in the carbon cycle. Photosynthesis occurs in chloroplasts where CO2 and water are converted to glucose and oxygen, whereas cellular respiration happens in mitochondria where glucose and oxygen are used to create ATP.
Step-by-step explanation:
The role of carbon in photosynthesis and cellular respiration is central to the energy and carbon cycles of the earth. In the process of photosynthesis, which occurs in the chloroplasts of plant cells, carbon dioxide (CO2) from the air and water (H2O) from the soil are transformed into glucose (C6H12O6) and oxygen (O2) in the presence of sunlight. The equation for photosynthesis can be summarized as: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. Glucose serves as an energy source for plants and other organisms.
During cellular respiration, which occurs in the mitochondria of both plant and animal cells, glucose and oxygen are used to produce energy in the form of ATP (adenosine triphosphate), along with byproducts of carbon dioxide and water. The equation for cellular respiration is the reverse of photosynthesis: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP. Thus, the oxygen produced by photosynthesis is used in cellular respiration, and the carbon dioxide produced by respiration is used in photosynthesis, creating a cyclical relationship.
Both processes are interconnected and help to maintain the levels of oxygen and carbon dioxide in the atmosphere, contributing to the larger carbon cycle. Photosynthesis and cellular respiration are key processes that allow life to thrive on Earth, supplying energy and recycling carbon through the environment.