Answer: More oxygen.
- A Less oxygen
- B More oxygen
- C No oxygen
- D Only water
Correct answer: B. More oxygen
Explanation: Fats are highly reduced, so oxidising them consumes more O<sub>2</sub> per CO<sub>2</sub> released, giving an RQ well below 1.
Aerobic respiration unfolds in three locations: glycolysis in the cytoplasm yields a small amount of ATP directly, the Krebs cycle in the mitochondrial matrix harvests electron carriers (NADH, FADH2), and the electron transport chain in the inner mitochondrial membrane uses those carriers to generate the bulk of the ATP, with O2 needed only at this final stage.
Concept context
Glycolysis, the Krebs cycle, the electron transport chain, fermentation, and the respiratory quotient. The cellular energy-release counterpart to photosynthesis.