Question

A fellow student is studying the differences between photosynthesis and cellular respiration. The student asks you to explain how cellular respiration uniquely contributes to the carbon cycle. In 3-5 sentences, describe the different ways that both photosynthesis and cellular respiration contribute to the carbon cycle.

Answer 1

Photosynthesis removes CO2 from the atmosphere and ocean and fixes it into organic molecules (like glucose), storing energy from sunlight and releasing O2. Cellular respiration oxidizes those organic molecules back to CO2 and H2O while releasing chemical energy for cells to use. Uniquely, respiration returns previously fixed organic carbon to the inorganic pool (atmosphere and water), powering the short-term biological carbon flux and enabling continual recycling of carbon. Together, photosynthesis and respiration form a tight biological loop that moves carbon between inorganic and organic forms.