The Carbon Cycle

The Carbon Cycle

The Carbon Cycle

• the exchange of carbon between living organisms (biotic) and their atmosphere (abiotic).

• In the carbon cycle, carbon is constantly removed from, and returned to, the environment.

The Carbon Cycle - 1. respiration

• releases energy and emits carbon dioxide to the surroundings.

• during respiration, organisms break down complex molecules containing carbon (like glucose and lipids) into small carbon dioxide molecules.

The Carbon Cycle - 2. photosynthesis

• plant takes in carbon dioxide from the air and use solar energy to synthesize glucose.

• this is converted into starch (a complex molecule.)

• therefore, the small carbon dioxide molecule (produced in respiration) has been converted into complex molecules of living organisms.

• these molecules are passed on to consumers in food webs and circulate to all living organisms.

The Carbon Cycle - 3. decomposition

• when living organisms die, cells break down and decompose.

• decomposition carried out by microorganisms in the soil (fungi/bacteria.)

• carbon is released as carbon dioxide gas from complex molecules containing carbon.

The Carbon Cycle - 4. combustion

• materials used for combustion (burning) derived from plants.

• the process of combustion releases the carbon stored in these materials as carbon dioxide gas.

  coal, oil, natural gas and wood