The goals of photosynthesis and cellular respiration are to make energy.
During photosynthesis, the energy from the sun is captured by chlorophyll (the green pigment that is housed within a chloroplast's thylakoids of a plant cell). The sunlight energy is used to convert carbon dioxide and water into oxygen gas and a sugar called glucose. The glucose, in turn, can be used by the plant as a readily available energy source or stored as starch for use at a later time.
Cellular respiration occurs in mitochondria of eukaryotic cells. It uses the glucose and oxygen produced during photosynthesis. Energy is stored within the bonds of glucose. As glucose is broken down, this energy is released. The oxygen and glucose is then converted into carbon dioxide, water, and ATP. ATP (adenosine triphosphate) is a molecule that can be readily used as a form of energy. It contains three phosphate groups.