Question

Choose the correct option regarding general respiratory quotient of organic acids.

• A. One
• B. Less than one
• C. More than one
• D. Zero

Answer 1

Answer: (C)

Respiratory Quotient:
R.Q. is the ratio of the volume of carbon dioxide released to the volume of oxygen taken in respiration and it is mathematically expressed as:
$R.Q. = \frac{Volume of C{O}_2 }{evolved}$
The value of R.Q. varies with the substrate. Thus the measurement of R.Q. gives some idea of the nature of the substrate being respired in a particular tissue. R.Q. is usually measured by Ganong's respirometer.
Organic acids: When organic acids are used as the respiratory substrate like malic acid, oxalic acid, etc. R.Q. value is generally more than one, except acetic acid whose value is 1. The breakdown of malic acid is as follows:
$C_4{H}_6{O}_5 + 3O_2 \to 4C{O}_2 + 3H_{2}O + Energy$$R.Q. = \frac{Volume of C{O}_2 }{evolved}= \frac{4}{3} = 1.33$
The R.Q. value of various organic acids is as follows:

1.14