Respiration in Plants Test - 14

The respiratory quotient (RQ) is used in calculations of basal metabolic rate (BMR). It is the ratio of the volume of carbon dioxide produced by the body to the volume of oxygen consumed by the body in respiration over a period of time. It depends on the type of respiratory substrate used during respiration. RQ of fat is about 0.7. RQ of carbohydrate is 1. RQ of organic acids is above 1. RQ of protein is 0.9. RQ value gives information about the source of energy an animal is using.
Thus, the correct answer is option A.

The electron transport chain along with oxidative phosphorylation involves the synthesis of energy-rich ATP molecules with the help of energy released during the oxidation of reduced coenzymes (NADH₂ and FADH₂) formed during glycolysis and the Krebs cycle. A total of 10 NADH₂ and 2 FADH₂ molecules are produced during aerobic respiration. They help in the formation of 32 ATP molecules.

Respiratory Quotient is CO₂/O₂
The respiratory quotient (R.Q) is the ratio of CO₂ produced to O₂ consumed, while food is being metabolized.
RQ = CO₂  eliminated / O₂ consumed
R.Q for proteins is less than 1 since, amount of CO₂ evolved is lesser than amount  O₂ consumed.
When organic acids are broken down as respiratory substrates under aerobic conditions the R.Q is more than one. Organic acids contain more oxygen than carbohydrates and therefore require less oxygen for their oxidation.

Pyruvate formed during glycolysis is oxidized CO² and H²O in Krebs cycle or Citric acid cycle or Tricarboxylic acid cycle. Krebs cycle involves in the oxidation of acetyl CoA into CO² and H²O.

So the correct option is 'Citric acid cycle, Tricarboxylic acid and Krebs cycle'.