Question

R.Q for organic acid is
A)1
B)>1
C)<1
D)0

Answer 1

Hint: Acids release carbon dioxide and oxygen. Respiratory Quotient or R.Q is defined as the ratio of the volume of carbon dioxide released to the volume of Oxygen absorbed in the process of respiration.

Complete answer:
RQ= $CO_2$ eliminated divided by $O_2$ consumed.

Respiratory Quotient also indicates which macronutrients are being metabolised to give us energy. The ratio RQ is measured in a definite time period and at standard temperature and pressure. It’s value can be zero , one, more than one and less than one depending on the variables. This is used to measure the basal metabolic rate or BMR of organisms,
Option A: 1
Respiratory Quotient of carbohydrate is 1 . Carbohydrate is a macronutrient which is metabolised to give energy and the R.Q calculates as 1. Therefore this is an incorrect option.
Option B:>1
Respiratory Quotients of organic acid such as malic acid , tartaric acid, oxalic acid are always greater than one. Therefore this is the correct option.
Option C:<1
Respiratory Quotients of fat and proteins are always less than one because their energy metabolism is different from carbohydrates. Therefore this is an incorrect option.
Option D: 0
The respiratory quotient of succulent plants are always zero because in this type anaerobic respiration of carbohydrate takes place at night when stomata are open. Therefore this is an incorrect option.

Hence, the correct answer is option (B)

Note: In aerobic respiration, when respiratory substrate is fat or protein, R.Q is less than 1. When carbohydrate is the substrate, R.Q is 1.
In anaerobic respiration, the respiratory quotient is more than 1,when carbohydrate is the substrate. But when carbohydrate is partially oxidised, like in succulent plants, the respiratory quotient is zero.