Based on the map of cellular respiration, why do we need to breathe in oxygen?
a) Oxygen is the final electron acceptor for lactic acid fermentation.
b) Oxygen is the final electron acceptor for alcohol fermentation.
c) Oxygen is the final electron acceptor for aerobic cellular respiration.
d) Oxygen is not important for the purposes of cellular respiration.

• A. Oxygen is the final electron acceptor for lactic acid fermentation.
• B. Oxygen is the final electron acceptor for alcohol fermentation.
• C. Oxygen is the final electron acceptor for aerobic cellular respiration.
• D. Oxygen is not important for the purposes of cellular respiration.

Answer: (C)

Verified step by step guidance

1. Understand the role of oxygen in cellular respiration: Oxygen is crucial in the process of aerobic cellular respiration, which occurs in the mitochondria of cells.
2. Identify the stages of aerobic cellular respiration: The process includes glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain (ETC).
3. Focus on the electron transport chain (ETC): This is the final stage of aerobic respiration where most of the ATP is produced.
4. Recognize the role of oxygen in the ETC: Oxygen acts as the final electron acceptor at the end of the electron transport chain. It combines with electrons and protons to form water.
5. Conclude why oxygen is essential: Without oxygen, the electron transport chain cannot function, halting ATP production and making oxygen indispensable for efficient energy production in aerobic respiration.