3-Phosphoglyceric acid (
3PG), or
glycerate 3-phosphate (
GP), is a
biochemically significant 3-carbon
molecule that is a metabolic intermediate in both
glycolysis and the
Calvin cycle. This chemical is often termed
PGA when referring to the Calvin cycle. In the Calvin cycle, 3-Phosphoglycerate is the product of the spontaneous split of an unstable 6-carbon intermediate formed by CO
2 fixation. Thus, two 3-phosphoglycerate molecules are produced for each molecule of CO
2 fixed.