Question

The Respiratory Quotient (RQ) value is less than one in:

• A. Organic acids
• B. Lipids
• C. Carbohydrates
• D. Glucose

Hint:

Lipids always show RQ < 1 because they consume more oxygen during oxidation.

Answer 1

The Correct Option is B

Step 1: Understanding Respiratory Quotient (RQ).
RQ is defined as: \[ RQ = \frac{CO_2 \, \text{produced}}{O_2 \, \text{consumed}} \] It depends on the type of respiratory substrate used.

Step 2: RQ values for different substrates.
Different biomolecules give different RQ values depending on their oxidation pattern.

Step 3: Carbohydrates and organic acids.
Carbohydrates generally have RQ = 1 because CO$_2$ produced equals O$_2$ consumed. Organic acids often have RQ ≥ 1 due to excess CO$_2$ production.

Step 4: Lipids metabolism.
Lipids require more oxygen for oxidation and produce relatively less CO$_2$, resulting in RQ < 1.

Step 5: Analysis of options.
- Organic acids: RQ ≥ 1
- Lipids: RQ < 1 (correct)
- Carbohydrates: RQ = 1
- Glucose: RQ = 1

Step 6: Final conclusion.
Therefore, RQ is less than one in lipids.