What is the role of NAD+ in the process of cellular respiration?

• A. It acts as an electron carrier, accepting electrons during glycolysis and the Krebs cycle.
• B. It provides the energy required to convert ADP to ATP.
• C. It breaks down glucose into pyruvate during glycolysis.
• D. It serves as the final electron acceptor in the electron transport chain.

Answer: (A)

Verified step by step guidance

1. Understand the process of cellular respiration, which includes glycolysis, the Krebs cycle, and the electron transport chain.
2. Recognize that NAD+ (Nicotinamide adenine dinucleotide) is a coenzyme involved in redox reactions, carrying electrons from one reaction to another.
3. During glycolysis and the Krebs cycle, NAD+ accepts electrons and becomes reduced to NADH. This is crucial for the transfer of energy.
4. NADH then carries the electrons to the electron transport chain, where it is oxidized back to NAD+, releasing the electrons to help generate ATP.
5. Conclude that NAD+ acts as an electron carrier, accepting electrons during glycolysis and the Krebs cycle, and is essential for the continuation of cellular respiration.