Final answer:
The oxygen consumed during cellular respiration is directly involved in the electron transport chain, the third and final stage of cellular respiration, where it acts as the final electron acceptor to form water and assist in the production of ATP.
Step-by-step explanation:
The oxygen consumed during cellular respiration is involved directly in the process known as the electron transport chain, which is the third stage of cellular respiration. This stage operates in the inner membrane of the mitochondrion and is where oxygen acts as the final electron acceptor to form water. Here, the electrons extracted from the food during the earlier stages of cellular respiration move down the electron transport chain, and as they reach oxygen, they help in the formation of water. The energy released from this electron transfer is used to pump protons across the mitochondrial membrane, generating a gradient that is then used to synthesize ATP (Adenosine Triphosphate).Therefore, the correct answer to which process or event directly involves the oxygen consumed during cellular respiration is the electron transport chain (option 3).