In an experiment, the carbon dioxide available to a C3 plant was labelled with a radioactive isotope and the amount of radioactivity in the chloroplast was measured. As photosynthesis proceeded, in which of the following molecules did the radioactivity first appear?
Use of radioactive 14C in photosynthesis studies led to the discovery that the first CO2 fixation product was a 3-carbon organic acid. The first product identified was 3-phosphoglyceric acid or in short PGA.