How does a cell generate energy? There are two pathways: one fast and one slow. The fast route occurs mainly in the protoplasm of the cell. Enzymes serially break down glucose into smaller and smaller molecules, and the reaction produces energy. Because the process doesn’t use oxygen, it is called anaerobic. In terms of energy, the end product of the fast pathway is two molecules of a chemical called adenosine triphosphate, or ATP.
