Yes, RQ > 1 occurs during anaerobic respiration when lactic acid is buffered by bicarbonate, producing extra CO2 beyond oxygen consumption. It can also occur during lipogenesis.

Understanding Respiratory Quotient

Quick Answer: The Respiratory Quotient (RQ) is the ratio of carbon dioxide produced to oxygen consumed during respiration. It indicates which substrate is being oxidized: carbohydrates give RQ = 1, fats ~0.7, proteins ~0.8-0.9.

Key Concepts

RQ = CO₂ eliminated / O₂ consumed. For glucose: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O, RQ = 6/6 = 1. For tripalmitin (fat): RQ ≈ 0.7. For proteins: RQ ~0.8-0.9. Mixed diet gives RQ ~0.85. RQ > 1 suggests anaerobic respiration or lipogenesis.

Solved Examples

Glucose Respiration
CO₂ = 6, O₂ = 6
RQ = 6/6 = 1.0
Carbohydrate metabolism

Fat Respiration
CO₂ = 16, O₂ = 23
RQ = 16/23 = 0.696
Lipid oxidation

Anaerobic Threshold
CO₂ = 110, O₂ = 100
RQ = 1.1
Hyperventilation or lactic acid buffering

FAQs

What does an RQ value of 1 indicate?

RQ = 1 indicates pure carbohydrate oxidation. It is the theoretical value for glucose respiration.

Can RQ exceed 1?

Yes, RQ > 1 occurs during anaerobic respiration when lactic acid is buffered by bicarbonate, producing extra CO₂ beyond oxygen consumption. It can also occur during lipogenesis.

Why is RQ useful in clinical settings?

It helps assess metabolic substrate utilization in critically ill patients. Indirect calorimetry uses RQ to determine energy expenditure and nutritional needs.