At the end of cellular respiration, the electrons are transferred to a final electron acceptor.  In aerobic cellular respiration, this molecule is

In aerobic cellular respiration, the final electron acceptor is oxygen (O₂). At the end of the electron transport chain, which is the last stage of cellular respiration, electrons are transferred to molecular oxygen. This process occurs within the mitochondria of eukaryotic cells. When oxygen accepts the electrons, it combines with protons (hydrogen ions) to form water (H₂O), which is a byproduct of cellular respiration.

The significance of oxygen as the final electron acceptor lies in its vital role in facilitating the production of ATP (adenosine triphosphate) through oxidative phosphorylation. This process allows cells to generate a large amount of energy—up to 36-38 ATP molecules per glucose molecule processed, making aerobic respiration much more efficient than anaerobic respiration, which does not utilize oxygen. The complete oxidation of glucose in the presence of oxygen is essential for sustaining the energy needs of aerobic organisms.