Respiration is the process which helps to break down the stored carbohydrates in the body to release energy. This takes place through the breakdown of C - C bonds of carbohydrates, to make the energy available to cells. Photosynthesis is a process which traps light energy and converts it into chemical energy that is stored in the bonds of carbohydrates like glucose. The synthesis of ATP in plant cells from ADP and phosphate, using radiant energy from sunlight during photosynthesis is called Photophosphorylation. Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown or storage of fats for energy.