The CO 2 is combined with the hydrogen left over from the water split in the light reactions. Some water molecules are produced as a waste product during this step. P.S. PGAL stands for phosphoglyceraldehyde. Four identical plants are grown under different colored light bulbs. Water molecules are split.
Carbon dioxide is used.
PGAL is formed. Light energy is absorbed by chlorophyll. The reactions occur in the stroma of the chloroplast. The reactions occur in the grana of the chloroplast. Glucose is formed.