Every plant going thorough photosynthesis its a chemical change which turns water and Carson dioxide into suger(gloucose) and oxygen. There is two steps in photosynthesis step one is called light dependent reaction and step two is called the Calvin cycle.
In step one light from the sun is absorbed by the corphll pigment in the chloroplasts this causes the excitement of electrons the light energy to chemical energy(ATP,NADPH),and causes H2O to break apart and release oxygen.
In step two ATP breaks carbon dioxide(CO2), and water apart to form gloucose which planet use to store energy. This takes place in the strama.