Respiration In Plants

The respiratory quotient (RQ), also known as the oxygen-to-carbon dioxide ratio, measures how much oxygen is used during respiration of a certain substrate. Most typical fats have an RQ of around 0.7. Numerous fatty acids are present in the Pisum sativum or pea seed, and these lipids are oxidised during germination. The RQ of a germination of Pisum sativum is therefore around 0.7, which is less than unity.

Any material or living thing has a respiratory quotient, which can be anywhere between 0.7 and 1.0.

Less oxygen is consumed or more carbon dioxide is produced by molecules with greater RQ levels.

A respiratory quotient is a number without dimensions. 

The respiratory quotient is used to determine the basal metabolic rate.

The respiratory quotient of carbohydrate oxidation frequently remains low because oxidising carbs requires more oxygen than oxidising fatty molecules.

The presence of insulin in substances raises the respiratory quotient because it improves the lipid storage of compounds during respiration.

Uses for the Respiratory Quotient 

• It can be used to determine the kind of the chronic ailment, liver cirrhosis.
• It is used to determine if a person is eating too much or too little.
• It's utilised to anticipate a diabetic patient's weight increase while they are not insulin-dependent.
• It is used to assess the functioning of the liver.

RQ are listed below for several respiratory substrates: 

RQ = 1.0 for carbohydrates.

The most prevalent respiratory substrates include carbohydrates like glucose. When all of the glucose is oxidised during aerobic respiration, the CO₂ production to O₂ consumption ratio is 1.0. This indicates that one molecule of CO2 is created and one molecule of O₂ is consumed for every molecule of glucose that is metabolised.

Lipids/Fats: RQ 0.7

Lipids, often known as fats, are energising molecules that are also used as respiratory substrates. Compared to carbohydrates, fatty acids create more reduced electron carriers (NADH and FADH2) during cellular respiration. An RQ value of around 0.7 results from a higher oxygen consumption rate in comparison to CO₂ production