Question

What is RQ for human fat?

Answer 1

Hint: RQ is the abbreviated form of respiratory quotient. It is the ratio of the amount of carbon dioxide produced by a cell or an organism to the amount of oxygen consumed by it.

Complete answer: The respiratory quotient or RQ refers to the ratio of the amount of produced by the body to the amount of consumed by the body.
1. It is dimensionless because it is a ratio.
2. RQ is also called the respiratory coefficient.
3. It may be used to determine the basal metabolic rate (BMR).
4. The value respiratory quotient value depends upon the type of the respiratory substrate.
5. If fats or lipids are a substrate for respiratory reactions, then the RQ value is less than 1.

Additional information: Practical applications of the respiratory quotient can be found in severe cases of chronic obstructive pulmonary disease, in which patients spend a significant quantity of energy on respiratory effort.
By increasing the number of fats in the diet, the respiratory quotient is driven down, causing a decrease in the amount of $CO_2$ produced.
This reduces the respiratory burden to reduce $CO_2$, hence decreasing the amount of energy spent on respirations.

So the correct answer is '0.703'

Note: By just looking at the value of respiratory quotient, we can say which macronutrients are being metabolized because RQ is specific for certain types of substrates, e.g. for the metabolic process involving solely lipids, RQ is 0.7, for carbohydrate molecules, it is 1, and RQ value is 0.8 for proteins.