Photosynthesis is the process in which plants use light energy to convert carbon dioxide and water into glucose (sugar) and oxygen. This process typically takes place within an organelle in a cell called a chloroplast. The first step of photosynthesis is the absorption of light energy from the sun. The light energy is then captured and used to split water molecules into oxygen and protons. The protons are then used to generate ATP through a process called photophosphorylation. This ATP is then used to convert the carbon dioxide into an organic compound (sugar) through a process called the Calvin Cycle. Finally, the oxygen that was generated from the splitting of the water molecules is released into the atmosphere.