The process by which carbon moves from carbon pools (such as the atmosphere, oceans, and soil) into living organisms is primarily through photosynthesis. Here’s how it works:
-
Atmospheric Carbon Dioxide: Carbon exists in the atmosphere mainly as carbon dioxide (CO2).
-
Photosynthesis: Plants, algae, and some bacteria absorb CO2 from the atmosphere during photosynthesis. This process occurs mainly in the chloroplasts of plant cells, where sunlight is captured by chlorophyll.
-
Conversion to Organic Matter: During photosynthesis, CO2 is converted into glucose (C6H12O6) and other organic compounds using energy from sunlight. The overall equation for photosynthesis can be simplified as: \[ 6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}6\text{H}{12}\text{O}_6 + 6 \text{O}_2 \] Here, carbon from carbon dioxide is assimilated into plant biomass.
-
Transfer Through the Food Chain: When herbivores eat plants, they consume the organic carbon in the form of carbohydrates, fats, and proteins. Carnivores then obtain carbon by consuming herbivores or other carnivores.
-
Decomposition: When living organisms die or produce waste, decomposers like bacteria and fungi break down the organic material, returning carbon to the soil or atmosphere in forms such as CO2 or methane (CH4).
Through these processes, carbon continuously cycles between inorganic and organic forms, making it available for living organisms. This cycle is a critical aspect of the global carbon cycle, which plays a vital role in regulating the Earth’s climate and supporting life.