What Role Does ATP Play in Photosynthesis?

Adenosine triphosphate, or ATP, is an organic compound that provides energy for many different metabolic processes. In the chloroplasts, ATP is a product of the first stage of photosynthesis, and it provides energy for the second stage. After photosynthesis is over, this nucleotide powers metabolism for the entire plant cell.

Chemiosmosis is the process by which plant cells produce ATP. A group of protons hurries over a membrane, and ATP molecules synthesize as a result. The process of passing over the membrane causes energy to leach out of the protons, and that energy creates the high-energy bonds within ATP.

After the second phase of photosynthesis begins, ATP provides the energy for the development of phosphoglycerate molecules and the conversion of those molecules into organic compounds. These organic compounds eventually combine to form six-carbon glucose. The plants then store glucose in different ways. Some collect starch molecules, others store them in underground stems called tubers and still others convert the energy to fructose, or fruit sugar. Table sugar, known as sucrose, is another product that is the result of glucose storage inside a plant.

After photosynthesis is over, ATP has other functions in the cell. It powers motility, cell division and biosynthetic reactions.