If the volume of CO ₂ evolved during respiration is less than the oxygen consumed, then the respiratory substrate would be ____.

Step-by-step solution

The ratio of the volume of CO₂ evolved to the volume of O₂ consumed during respiration is known as the Respiratory Quotient (RQ). RQ = Volume of CO₂ evolved Volume of O₂ consumed According to the given condition, the volume of CO₂ evolved is less than the volume of O₂ consumed. This implies that the value of RQ is less than 1. For carbohydrates such as glucose, fructose, and galactose, the volume of CO₂ evolved is equal to the volume of O₂ consumed, giving an RQ equal to 1. For fats, the amount of oxygen in their m