The series of processes by which carbon compounds are interconverted in the environment, chiefly involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.
Cellular respiration is the process where energy that was stored in nutrients within the body is released. Both autotrophs and heterotrophs use cellular respiration. Glucose and oxygen are combined to create carbon dioxide, water, and energy. There are two different types of cellular respiration: anaerobic and aerobic. When oxygen is neither required nor consumed it is anaerobic respiration. When oxygen is required and consumed it is aerobic restoration.