RBSE Class 11 Biology Notes Chapter 14 Respiration in Plants

These comprehensive RBSE Class 11 Biology Notes Chapter 14 Respiration in Plants will give a brief overview of all the concepts.

RBSE Class 11 Biology Chapter 14 Notes Respiration in Plants

→ Energy is required for completion of different metabolic process in each organism.

→ In plants, energy is stored in the form of organic substances which are synthesized by photosynthesis, sis The energy is released by the oxidation of these organic substances.

→ In plants, anabolic and catabolic process continuously goes on, which are synthetical and destructive respectively and these are collectively called metabolic process

→ The respiration is a Characteristic feature in each organism. In this O₂ is absorbed and CO₂ is evolved. The respiration in plants is differ from that of in animals:

• Plants do not breath,
• Respiration can take place in the absence of O₂ in some prokaryotes but CO₂ does not evolve in this,
• During day, there is no necessity of O₂ from atmosphere is some plants. The O₂ produced during photosynthesis is used in respiration by animals and CO₂ evolved in animal’s respiration is used in photosynthesis,

→ The respiration is an oxidation process, occurs in living cells, in which various complex organic substances (such as: glucose , starch, sugar, fats, proteins, organic acid etc.) oxidizing to form energy, which is used in various metabolic processes and stored in ATP. In this process CO₂ is released

→ The combustion is also a oxidation process. In this also energy is released from organic substances but it is a chemical process which does not require living cell.

→ When in plants, there is no need of exchange of CO₂ and O₂ from atmosphere and that fulfils in plant, then this condition is called compensation point

→ The respiration process is of two types:

• Aerobic respiration and
• Anaerobic respiration

→ When respiration takes place in the presence of oxygen, it is called aerobic respiration and such organisms are called aerobic organisms. In this process CO₂, water and large amount of energy are formed by complete oxidation of food materials.
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy

→ When respiration takes place in the absence of O₂ is called anaerobic respiration and the organisms are called anaerobic organisms. In this ethyl alcohol, or other organic acids, CO₂ and less energy are formed by incomplete oxidation of food materials.
C₆H₁₂O₆ →  2C₂H₅OH + 2CO₂ + energy

→ Fermentation is a type of anaerobic respiration but it occurs outside the cell of organism by chemical reactions.

→ In respiration, generally, carbohydrate is respiratory substance. Aerobic .and anaerobic respiration takes place in two steps. The first step of both the process is same. It does not require O₂. The two steps of respiration are glycolysis and Kreb’s cycle.

→ Glycolysis process takes place in cytoplasm. In this one molecule of glucose forms two molecules of pyruvic acid through various chemical reactions

→ When pyruvic acid formed in glycolysis oxidises in the absence of O₂ to forms ethyl alcohol and CO₂, then this process is called anaerobic respiration.
 
→ When the oxidation of pyruvic acid takes place in the presence of O₂, CO₂ and water are formed, then it is called aerobic respiration. It is also called Kreb’s cycle.

→ Before entering into Kreb’s cycle, pyruvic acid converts into acetyl Co-A. Thus acetyl Co-A is mediator of glycolysis and Kreb’s cycle.

→ Kreb’s cycle is also called tricarboxylic acid cycle (TCA) and occurs in mitochondrion.

→ Respiration: Oxidation process of food materials.

→ Combustion: It is also an oxidation process but it differs from respiration.

→ Anabolism: The process in which new substances are synthesized.

→ Catabolism: The process in which complex substances are degraded.

→ Metabolism: Anabolism and catabolism are collectively called metabolism.

→ Glycolysis: A series of reactions taking place in cytoplasm in which pyruvic acid is formed from glucose.

→ Respiratory chain enzymes: Enzymes that are found in F₁ particle of mitochondria and takes part in electron transport.

→ Aerobes: Organisms that survive in the presence of oxygen.

→ Anaerobes: Organisms that cannot survive in the presence of oxygen only.

→ Fermentation: The respiration process takes place in the absence of oxygen in some micro-organisms.

→ Respiratory Quotient (RQ): The ratio of volume of evolved CO₂ and volume of absorbed O₂.

→ Respirometer: A device used in measurement of RQ.