Which one of the following coenzymes is not a part of the β-oxidation pathway?

• A. ATP
• B. FADH₂
• C. CoQ
• D. CoA
• E. NADH

Answer: (C)

Verified step by step guidance

1. Understand the β-oxidation pathway: β-oxidation is the process by which fatty acids are broken down in the mitochondria to generate acetyl-CoA, NADH, and FADH2, which are used in the electron transport chain to produce ATP.
2. Identify the coenzymes involved in β-oxidation: The main coenzymes involved are FAD, NAD+, and CoA. FAD is reduced to FADH2, NAD+ is reduced to NADH, and CoA is used to form acetyl-CoA.
3. Recognize the role of ATP: ATP is not directly involved as a coenzyme in the β-oxidation pathway. It is the end product of cellular respiration, where the reduced coenzymes (NADH and FADH2) are used to generate ATP in the electron transport chain.
4. Consider the role of CoQ (Coenzyme Q): CoQ is part of the electron transport chain, not directly involved in the β-oxidation pathway. It transfers electrons from complexes I and II to complex III in the mitochondria.
5. Conclude which coenzyme is not part of the β-oxidation pathway: Based on the roles of each coenzyme, CoQ is not directly involved in the β-oxidation pathway, as it functions in the electron transport chain.