Question

Choose the correct answer from the alternatives given:
The Respiratory Quotient (R.Q.) is less than one in:
a. Fats
b. Carbohydrates
c. Proteins
d. Organic acids

Answer 1

Hint: Respiratory Quotient is defined as the ratio of the change in volume of carbon dioxide to that of oxygen consumed by an organism, tissue or a cell. It is used to calculate Basal Metabolic Rate (BMR). It may be used to analyse liver functions and diagnose the diseases of the liver.

Complete answer:
Respiratory Quotient may be less than, more than or equal to one. The classification is as follows:
• The RQ value is one during aerobic respiration. When respiration takes place in the presence of oxygen, it is known as aerobic respiration. It occurs in carbohydrates.
• The RQ value is less than one in aerobic respiration of fats and proteins.
• The RQ value is zero in succulents which respire during the night.
• The RQ value is more than one in tartaric, malic and oxalic acid.

Based on the values provided above, Respiratory Quotient is less than one in fats and proteins.
Hence, the correct answers are option (A) and (C).

Additional information:
Normal Respiratory Quotient is defined as the RQ which ranges between values 0.7 and 1. Molecules which are highly oxidized will need less oxygen to metabolize completely. This results in higher RQ. An example of such molecules is glucose. Contrary to this, molecules which are lowly oxidized need less oxygen to metabolize completely have lower Respiratory Quotient.

Note: Confusion may arise between RER and RQ. RER is defined as the Respiratory Exchange Ratio. RER runs parallel with RQ by measuring the air that is ejected. It may be used to estimate RQ. The basic difference between the two is that RQ measures carbon dioxide at metabolic level whereas RER measures carbon dioxide which is produced as a result of buffering.