The ATP (adenosine triphosphate) molecules perform its functions by breaking and reconstructing bonds with the phosphate groups. When the ATP is converted into ADP (adenine diphosphate), the ATP gets to be spent to release energy. Once ATP is used, it becomes ADP. Then, ADP is recycled and recharged into the mitochondria and comes out again as ATP.

Photosynthesis harnesses the energy from the sun to manufacture their own food. This process involves the conversion of carbon dioxide and water into chemical energy, which is in the form of glucose, and oxygen.

When the ATP is converted into ADP (adenine diphosphate), the ATP gets to be spent to release energy. Once ATP is used, it becomes ADP. Then, ADP is recycled and recharged into the mitochondria and comes out again as ATP. In this case, ADP is like a partially-charged battery. Once it combines with a phosphate group, it gets to be fully-charged as ATP, which is ready to be used again.

The diagram below shows the role of photosynthesis in converting light energy into chemical energy.

The conversion of energy between photosynthesis and solar cells are alike in terms of the way they harness the sun’s energy to make chemical energy. However, they differ in terms of the end products.

Photosynthesis uses solar energy to produce oils, glucose, and other complex carbohydrates that are stored as chemical energy. On the other hand, solar cells are considered as an artificial photosynthetic system that uses sunlight to make energy-rich molecules, such as methane and hydrogen, that can be stored as chemical energy in the form of fuel.