Main chemical reactions carried out in this cycle and their classification

Photosynthesis:

Photosynthesis is a complex series of reactions carried out by algae, phytoplankton and the leaves in plants, which utilize the energy from the sun. The simplified version of this chemical reaction is to utilize carbon dioxide molecules from the air and water molecules and the energy form the sun to produce a simple sugar such as starch, fats, proteins, enzymes, and DNA/RNA i.e all of the other molecules in living plants. All of the "matter/stuff" of a plant ultimately is produced as a result of this photosynthesis reaction.

Sedimentation:

Carbon dioxide is slightly soluble and is absorbed into bodies of water such as the ocean and lakes. It is not overly soluble as evidenced by what happens when a can of carbonated soda such as Coke is oppened. Some of the dissolved carbon dioxide remains in the water, the warmer the water the less carbon dioxide remains in the water.

Combustion:

Combustion occurs when any organic material is reacted (burned) in the presence of oxygen to give off the products of carbon dioxide and water and energy.

http://www.elmhurst.edu/~chm/vchembook/306carbon.html