Which molecule is essential for aerobic respiration to take place?

• A. Carbon dioxide (\(CO_2\))
• B. Lactic acid
• C. Oxygen (\(O_2\))
• D. Glucose (\(C_6H_{12}O_6\))

Answer: (C)

Verified step by step guidance

1. Understand the process of aerobic respiration: Aerobic respiration is a metabolic pathway where cells generate energy (ATP) by breaking down glucose (\(C_6H_{12}O_6\)) in the presence of oxygen (\(O_2\)). It occurs in the mitochondria and involves glycolysis, the citric acid cycle, and oxidative phosphorylation.
2. Identify the role of oxygen (\(O_2\)): Oxygen is the final electron acceptor in the electron transport chain during oxidative phosphorylation. Without oxygen, the chain cannot function, and ATP production is significantly reduced.
3. Compare the given molecules: Carbon dioxide (\(CO_2\)) is a byproduct of aerobic respiration, lactic acid is produced during anaerobic respiration, and glucose (\(C_6H_{12}O_6\)) is the fuel molecule broken down for energy. Oxygen (\(O_2\)) is essential for aerobic respiration to proceed.
4. Recognize the importance of oxygen (\(O_2\)): Oxygen enables the complete oxidation of glucose, leading to the production of a high yield of ATP compared to anaerobic respiration.
5. Conclude that oxygen (\(O_2\)) is the correct answer: Oxygen is indispensable for aerobic respiration as it drives the electron transport chain and allows efficient energy production.