The primary fuel for aerobic respiration is glucose. During this process, glucose is broken down in the presence of oxygen to produce ATP (adenosine triphosphate), the energy currency of cells. The breakdown of glucose involves several metabolic pathways, including glycolysis, the Krebs cycle, and the electron transport chain. Ultimately, aerobic respiration yields a significant amount of ATP and produces carbon dioxide and water as byproducts. This efficient energy extraction allows organisms to carry out various biological processes necessary for survival, growth, and reproduction.