Here's why:
* Electron Transport Chain: The electron transport chain (ETC) is a series of protein complexes embedded in the inner mitochondrial membrane. This chain's primary function is to transfer electrons from electron carriers like NADH and FADH2 to a final acceptor.
* Energy Production: The energy released during this electron transfer is used to pump protons across the inner mitochondrial membrane, creating a proton gradient. This gradient drives ATP synthesis, the primary energy currency of the cell.
* Oxygen's Role: Oxygen, with its high electronegativity, acts as the final electron acceptor in the ETC. It accepts electrons from cytochrome c oxidase, the last complex in the chain. This acceptance results in the formation of water (H2O) as a byproduct.
Without oxygen, the ETC would shut down, and the cell would be unable to produce ATP efficiently.
