What substance is oxidized during cellular respiration?

• A. Oxygen
• B. Water
• C. Glucose
• D. Carbon dioxide

Answer: (C)

Verified step by step guidance

1. Understand the process of cellular respiration: Cellular respiration is a metabolic process that converts glucose into energy in the form of ATP, with the consumption of oxygen and the production of carbon dioxide and water.
2. Identify the role of glucose: In cellular respiration, glucose (C₆H₁₂O₆) is the primary fuel molecule that is broken down to release energy.
3. Define oxidation in biological terms: Oxidation involves the loss of electrons from a molecule. In the context of cellular respiration, the substance that loses electrons is considered oxidized.
4. Determine which substance is oxidized: During cellular respiration, glucose is oxidized. It loses electrons and hydrogen atoms, which are transferred to electron carriers like NAD⁺, forming NADH.
5. Recognize the overall reaction: The overall chemical equation for cellular respiration is C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP). Here, glucose is oxidized to carbon dioxide, while oxygen is reduced to water.