Theory:

Functions of mitochondria:
  • Mitochondria is the organelle involved in cellular respiration. As they generate large amounts of ATP they are known as the power houses of the cell.
  • It aids the cells in maintaining a proper calcium ion concentration.
  • It regulates the metabolic activities of the cells by generating large amounts of ATP.
Respiration:
Respiration is a process that involves gaseous exchange between the organism and the environment.  Based on their mechanism it is of two types:
  1. External respiration
  2. Cellular respiration.
1.  External respiration:
 
Just like animals plants obtain oxygen from the environment and release carbon dioxide and water in the form of water vapour (recall transpiration from Grade IX). This physical process is known as external respiration.
 
2.  Cellular respiration:
Biochemical process occurs within cells where the food is oxidized to obtain energy, this is known as cellular respiration.
Cellular respiration takes place in both the cytosol and mitochondria of cells. It is of two types based on the presence and absence of oxygen:
  • Aerobic respiration
  • Anaerobic respiration
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Types of cellular respiration
Aerobic respiration:
It is a type of cellular respiration during which the organic food is completely oxidized into carbon dioxide, water and energy in the presence of oxygen. This type of cellular respiration occurs in majority of the plants and animals in their mitochondria.
 
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A generalized equation for aerobic respiration
  
The amount of ATP generated through the process of aerobic respiration is greater than the ATP generated through anaerobic respiration.
 
The process of cellular respiration occurs through various stages. Let us look into this in our next theory.