The oxygen consumed during cellular respiration is involved directly in:

The oxygen consumed during cellular respiration is involved directly in:

A) glycolysis

B) accepting electrons at the end of the electron transport chain

C) the citric acid cycle

D) the oxidation of pyruvate to acetyl CoA

E) the phosphorylation of ADP to form ATP

Answer: B) accepting electrons at the end of the electron transport chain

In cellular respiration, oxygen is directly concerned with the reduction that occurs at the terminal end of the electron transport series. This process takes place in the inner membrane of mitochondria and the conservation of energy is checked. This process of passing the electrons through various protein complexes in the chain involves the release of energy which is then used to transport protons through the intermembrane space. Thus, at the end of this chain, oxygen as the final acceptor of the electron occurs by attacking the electrons and protons and forming water. Thus, this role of oxygen is important in maintaining the flow of electrons and the gradient of protons, which ultimately contribute to the creation of ATP via oxidative phosphorylation. If oxygen is not used as the last recipient of the electrons, then the process comes to a stop and greatly decreases ATP synthesis in aerobic organisms.