Question

$2(C_{51}H_{98}O_{6}) + 145\,O_{2} \longrightarrow 102\,CO_{2} + 98\,H_{2}O + \text{energy}$ The Respiratory Quotient (RQ) of a biomolecule used for respiration, as per the above equation, would be :

• A. 1
• B. Less than 0.7
• C. Between 0.5 and 0.95
• D. Between 1.25 and 2

Hint:

Remember the standard RQ values: Carbohydrates = 1.0, Proteins $\approx$ 0.9, and Fats = 0.7.

Answer 1

The Correct Option is B

The Respiratory Quotient (RQ) is defined as the ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed during respiration. The calculation based on the provided balanced chemical equation for Tripalmitin (a fat) is as follows:
• Formula: $RQ = \frac{\text{Volume of } CO_{2} \text{ evolved}}{\text{Volume of } O_{2} \text{ consumed}}$
• Values from Equation: $CO_{2}$ evolved = 102 molecules; $O_{2}$ consumed = 145 molecules.
• Calculation: $RQ = \frac{102}{145} \approx 0.7$ In the given options, $0.7$ falls under the category of being "Less than 1.0". However, strictly speaking for fats, the value is $0.7$. Since the options provide specific ranges, and $102/145$ is exactly $0.703$, it is generally recognized as being less than $1.0$. Most textbooks specify that for fats, RQ is always less than $1.0$ (typically $0.7$).