Question

Define respiratory quotient. Write it's value for carbohydrates

Answer 1

The ratio of the volume of CO${}_2$ evolved to that of the volume of O${}_2$ consumed during the process of respiration is called as Respiratory Quotient (RQ) or Respiratory ratio.

RQ = $\frac{VolumeofC{O}_{2}evolved}{Volumeof{O}_{2}consumed}$

This RQ depends upon the type of respiratory substrate use during respiration. The value for Carbohydrates is 1 i.e., they are completely oxidized because an equal amount of Carbon dioxide and oxygen are evolved and consumed respectively as shown in the equation below :

C${}_6$H${}_1$${}_2$O${}_6$ + 6O${}_2$ $\to$ 6CO${}_2$ + 6H${}_2$O + Energy

RQ = 6CO${}_2$/6O${}_2$ = 1