Question

Protein-rich pulses have RQ
(a)One
(b)More than one
(c)Less than one
(d)None of the above

Answer 1

Hint Respiratory quotient is also termed as the respiratory ratio (RQ) and is defined as the volume of carbon dioxide released divided by the volume of oxygen absorbed during respiration. It’s a dimensionless quantity and is used in calculating basal metabolic rate when estimated from carbon dioxide production to oxygen absorption.

Complete answer:
The respiratory quotient (RQ) is a ratio between ${ CO }_{ 2 }$ produced to ${ O }_{ 2 }$ consumed.
RQ = $\dfrac { { CO }_{ 2 }Eliminated }{ { O }_{ 2 }Consumed }$
Most of the energy comes from food containing carbon, hydrogen, and oxygen. Examples include fat, carbohydrates, protein, and ethanol. Their metabolism is represented by the equation:
${ C }_{ x }{ H }_{ y }{ O }_{ z }+\left( x+\dfrac { y }{ 4 } -\dfrac { z }{ 2 } \right) { O }_{ 2 }\rightarrow x{ CO }_{ 2 }+\dfrac { y }{ 2 } { H }_{ 2 }O$
The RQ for protein metabolism can be demonstrated by the chemical equation representing oxidation of albumin: ${ C }_{ 72 }{ H }_{ 112 }{ N }_{ 18 }{ O }_{ 22 }\rightarrow { 63CO }_{ 2 }+38{ H }_{ 2 }O+{ SO }_{ 3 }$
The respiratory quotient for proteins is: RQ = $\dfrac { 63{ CO }_{ 2 } }{ 77{ O }_{ 2 } } $ = 0.8

Additional information:
The respiratory quotient (RQ) is calculated to study basal metabolic rate (BMR). It is the ratio of the quantity of carbon dioxide produced to the quantity of oxygen consumed by the body in respiration over a specific duration. It can vary and majorly depends on the category of respiratory substrate used during respiration. This value also tells us about the type of macronutrients that are being metabolized, as different energy pathways are used for fats, carbohydrates, and proteins.

So, the correct answer is ‘less than 1’.

Notes: The Respiratory Quotient is 0.7 for lipids, it is 0.8 for proteins, and for carbohydrates, it is 1.0. Since most of the time, food is composed of both fats and carbohydrates. Therefore, the respiratory quotient of a mixed diet is 0.8 approximately.