During aerobic respiration which takes place in the mitochondria of cells, glucose reacts with oxygen to form 36 molecules of adenosine triphosphate or A.T.P. as well as the wastes carbon dioxide and water vapor. A.T.P. provides the cell with the energy to live. Glucose contains chemical energy that originated with light energy from the sun. Plants capture that energy in their chloroplasts and the inorganic molecules carbon dioxide and water are joined forming glucose(an organic molecule) and oxygen. In the bonds between the atoms of glucose, there is chemical energy, which gets released during respiration.