Final answer:
Oxygen is the final electron acceptor in the Electron Transport Chain (ETC), which is a series of membrane-bound carrier molecules located in the inner mitochondrial membrane. If there is no oxygen present, the ETC becomes backed up, leading to the shutdown of other pathways and cell death.
Step-by-step explanation:
The relationship between the Electron Transport Chain (ETC) and oxygen is that oxygen is the final electron acceptor in the ETC. The ETC is a series of membrane-bound carrier molecules located in the inner mitochondrial membrane. As electrons are passed from one carrier to another, they lose energy, and some of that energy is used to pump hydrogen ions across the membrane. In the fourth protein complex, the electrons are accepted by oxygen, forming water. If there is no oxygen present, the ETC becomes backed up and eventually shuts down, leading to the shutdown of other pathways and ultimately cell death.