Hey,

The exchange of carbon between the lithosphere, Hydrosphere and atmosphere of the earth is termed as the carbon cycle.

Carbon constitute 49% of the dry weight just next to water constituents on earth and it is used by plants to make food that is for photosynthesis.

There are a sequence of steps related to the carbon cycle on each sphere of earth and thus like the terrestrial uptake, plant Biomass and soil carbon exchange in the lithosphere, Microbial respiration and plant usage in atmosphere, Phytoplankton photosynthesis, air sea gas exchange in hydrosphere form the carbon cycle.

You can get the diagram from any search engine.

I hope this helps.

All the best!