Carbon is essential for the survival, growth and reproduction of living things. It is a finite resource that comes in different forms and transfers from living to non-living things in various ways. Carbon stays balanced with other chemical reactions in the air and bodies of water through the carbon cycle.
Carbon is a component of both living and non-living things. Living organisms consist of organic carbon, while non-living things are comprised of inorganic carbon. Plants obtain carbon from the atmosphere in the form of carbon dioxide, which they need for photosynthesis. They convert inorganic carbon into organic carbon in the form of sugar and starch, which they add to their tissues. Animals acquire carbon by consuming plants and feeding on other animals.
Carbon changes to an inorganic state when animals exhale carbon dioxide. Bacteria and fungi disintegrate the bodies of dead plants and animals through decomposition, which releases carbon back into the atmosphere. The remains of plants and animals sometimes do not entirely decompose, and they become fossilized. When this occurs, carbon gets stored in a rock, and the fossils can be used as fossil fuels after millions of years. Carbon is released into the air through the process called carbon dioxide emission, wherein burning various fossil fuels produces different amounts of carbon dioxide, carbon monoxide and soot.