Phosphoglyceric acid or PGA is the first stable outcome of photosynthesis that goes through the process of reduction. The six molecules of 3-PGA are reduced to give six molecules of a chemical compound known as G3P or glyceraldehyde-3-phosphate.
During the conversion, six molecules of both NADPH and ATP are utilized. In this process, there is a gain of electrons by 3-PGA. NADPH is oxidized to NADP+ in the process of providing electrons, and energy is provided by ATP.