What is the role of oxygen in aerobic cellular respiration?

• A. Oxygen is used to break down glucose during glycolysis.
• B. Oxygen is converted into ATP during the Krebs cycle.
• C. Oxygen acts as the final electron acceptor in the electron transport chain.
• D. Oxygen is a substrate for the enzyme hexokinase.

Answer: (C)

Verified step by step guidance

1. Understand the process of aerobic cellular respiration, which includes glycolysis, the Krebs cycle, and the electron transport chain.
2. Recognize that glycolysis occurs in the cytoplasm and does not require oxygen; it breaks down glucose into pyruvate.
3. Identify that the Krebs cycle occurs in the mitochondria and generates electron carriers (NADH and FADH2) but does not directly use oxygen.
4. Learn that the electron transport chain is the final stage of aerobic respiration, located in the inner mitochondrial membrane, where electrons are transferred through a series of proteins.
5. Comprehend that oxygen acts as the final electron acceptor in the electron transport chain, combining with electrons and protons to form water, which is crucial for the continuation of the electron flow and ATP production.