The organisms have a important function in the carbon cycle, being them able to storage and exchange carbon, the living being are made of organic molecules that have carbon as one of the main components being also part of the carbon of the organisms stored as reservoirs. The processes such as respiration, excretion, and decomposition releases the arbon into the environment, while photosynthesis, and food can replenish the carbon molecules inside de organisms. The fact that organisms can storage this molecule is really fundamental to the carbon cycle, since it makes possible that reservoirs have the carbon in the Earth's in constant moving, going from reservoir to reservoir (from animals to the atmosphere, and from atmosphere to plants), making possible the constant recycling of carbon on the planet.