The respiratory quotient varies due to

Step-by-step solution

The value of R.Q. always depends upon the chemical nature of the substrate. In respiration, many types of high energy compounds are oxidized. These are called respiratory substrate or respiratory fuel and include carbohydrates, fats and protein. Carbohydrates such as glucose, fructose (hexoses), sucrose (disaccharide) or starch, insulin, hemicellulose (polysaccharide), etc; are the main substrates. The energy present in one gram carbohydrate is 4.4 Kcal or 18.4 kJ. Under certain conditions (mainly when carbohydrate