the circulation of carbon between living organisms and their surroundings. Carbon dioxide from the atmosphere is synthesized by plants into plant tissue, which is ingested and metabolized by animals and converted to carbon dioxide again during respiration and decay
2.
four thermonuclear reactions believed to be the source of energy in many stars. Carbon nuclei function as catalysts in the fusion of protons to form helium nuclei
carbon cycle in American English
1.
the cycle by which plants through photosynthesis use atmospheric carbon dioxide to produce carbohydrates, which are in turn metabolized by animals to decomposition products that return carbon dioxide to the atmosphere
2.
a cyclic series of thermonuclear reactions in the interior of some stars, involving carbon as a catalyst and producing large quantities of energyby the transformation of hydrogen into helium