- A Proteins mainly, since amino acid oxidation usually yields RQ above 1 in typical laboratory settings
- B Fats, since their high hydrogen content raises the RQ above 1 under normal conditions as generally observed
- C Pure carbohydrates, since glucose oxidation usually gives an RQ above 1 as frequently documented in most reference accounts
- D Organic acids, which are more oxidized than carbohydrates and release relatively more CO2 per O2 consumed
Correct answer: D. Organic acids, which are more oxidized than carbohydrates and release relatively more CO2 per O2 consumed
Explanation: Organic acids are already partially oxidized, so their respiration releases relatively more CO2 per O2 consumed, giving an RQ greater than 1; pure carbohydrate respiration gives RQ = 1, and fat/protein respiration gives RQ less than 1.
Concept context
Glycolysis, the Krebs cycle, the electron transport chain, fermentation, and the respiratory quotient. The cellular energy-release counterpart to photosynthesis.