Respiration in Plants

Synopsis

Respiration 

• Respiration is a catabolic process of releasing energy from simple sugar glucose for carrying out various life processes.
  
  

Respiratory Structures in Plants 

• Plants do not have a special respiratory organ for respiration. All parts of the plant such as the root, stem and leaves respire independently.
• Transfer of respiratory gases from one part to another is very less. Exchange of gases in plants occurs by simple diffusion.

Respiration in Leaves 

• Plants take in oxygen and give out carbon dioxide gas through the stomata. The process of diffusion is responsible for this gaseous exchange. 
• Large intracellular spaces ensure that all cells are in contact with the air that enters through the stomatal opening.
  
  
  
  
• The atmospheric oxygen first diffuses into the stomata and then into the cells of the leaves. This oxygen is used up by the plants for respiration, resulting in the formation of carbon dioxide.
• When the concentration of carbon dioxide in the cells increases, the stomata opens and releases the gas into the atmosphere.

Respiration in Stem 

• The stem of plants has minute openings on their surfaces called lenticels which help in the exchange of gases. 
• The barks of woody plants have lenticels for the exchange of gases.
  
  

Respiration in Roots

• The root system of plants absorbs oxygen from the air trapped in between the soil particles by the process of diffusion. 
• Oxygen from the soil diffuses into the root hair of the piliferous layer. The oxygen further diffuses into the other cells of the root. 
• Root hair is present only in the piliferous layer of the root. The rest of the root is covered by a layer of dead cells.
• The dead cells have lenticels on them. Gaseous exchange between the soil and inner living cells of the root occurs through these lenticels.
  
  

Differences between Aerobic and Anaerobic Respiration in Plants

Characteristics of Respiration in Plants