Which of the following indicates the role of oxygen in cellular respiration?

Oxygen plays a crucial role in cellular respiration as it serves as the final electron acceptor in the electron transport chain. During this process, electrons that are derived from the breakdown of glucose are transferred through a series of protein complexes. At the end of this chain, oxygen combines with the electrons and protons (hydrogen ions) to form water. This step is essential for the maintenance of the proton gradient that drives ATP synthesis through oxidative phosphorylation. Without oxygen to accept the electrons, the entire process would become clogged, halting ATP production and causing the cell to switch to less efficient anaerobic pathways for energy production. This highlights the fundamental role oxygen plays in facilitating efficient energy extraction from nutrients.