Question

The R.Q. is 1 for ______

• A. Carbohydrate oxidation
• B. Fat metabolism
• C. Protein metabolism
• D. None of the above

Answer 1

The correct option is A

Carbohydrate oxidation

The respiratory quotient is calculated as the ratio of the volume of carbon dioxide (CO₂) produced to the volume of oxygen (O₂) used, or VCO₂/VO₂. The respiratory quotient typically ranges between 0.7 and 1.0, is an indicator of metabolic fuel or substrate use in tissues.

Carbohydrates: The respiratory quotient for carbohydrate metabolism can be demonstrated by the chemical equation for the oxidation of glucose:

C6H12O6 + 6 O2 → 6 CO2+ 6 H2O

Because the gas exchange in this reaction is equal, the respiratory quotient for carbohydrates is: RQ = 6 CO2 / 6 O2= 1.0