Comparative catabolism — In what major ways are the catabolic pathways of sugars (carbohydrates) and fatty acids similar with respect to energy capture and central metabolism?

Introduction / Context:
Whether the starting fuel is glucose or a long-chain fatty acid, cells channel carbon into a few universal hubs to extract energy. Recognizing the shared features of carbohydrate and lipid catabolism helps explain why diverse foods ultimately power the same ATP-generating machinery.

Given Data / Assumptions:

• Glucose is degraded via glycolysis to pyruvate and then to acetyl-CoA.
• Fatty acids undergo beta-oxidation, producing acetyl-CoA, NADH, and FADH2.
• Acetyl-CoA enters the TCA cycle; high-energy electrons are passed to the electron transport chain.

Concept / Approach:
Identify convergence points and energy capture. Both pathways converge on acetyl-CoA and the TCA cycle, generate reduced cofactors (NADH, FADH2), and capture energy as ATP or GTP at the substrate level and through oxidative phosphorylation driven by the electron transport chain.

Step-by-Step Solution:

Verification / Alternative check:
Oxygen consumption and respirometry show similar downstream ETC behavior regardless of whether the upstream fuel is glucose or fat; only the upstream pathways differ in initial steps and regulation.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming only carbohydrates use the TCA cycle; overlooking that fatty acid acetyl-CoA also feeds the same cycle.

Final Answer:
All of the above.