Phosphoglycolate is produced as a byproduct of photorespiration. This arises from an oxygenase activity of the enzyme rubisco, which produced 3-phosphoglycerate and phosphoglycolate in the presence of oxygen. This reaction, which occurs under conditions of high oxygen concentration, is an inefficient aspect of photosynthesis. Phosphoglycolate's ultimate fate in the plant is to be converted to the amino acid glycine.