2. Life Processes in Living Organisms L-03

Anaerobic respiration in living organisms/ cells :


  • Some organisms cannot live in presence of oxygen. 
  • Ex. Many bacteria. 
  • Such living organisms have to perform anaerobic respiration for energy production. 
  • Glycolysis and fermentation are two steps of anaerobic respiration. 
  • Glucose is incompletely oxidized and less amount of energy is obtained in this type of respiration. 
  • Pyruvic acid produced through glycolysis is converted into other organic acids or alcohol with the help of some enzymes in this process. This is called as fermentation. 
  • Some higher plants, animals and aerobic microorganisms also perform anaerobic respiration instead of aerobic respiration if there is depletion in oxygen level in the surrounding.
  • Ex. Seeds perform anaerobic respiration if the soil is submerged under water during germination. 
  • Similarly, our muscle cells also perform anaerobic respiration while performing the exercise. 
  • Due to this, less amount of energy is produced in our body and lactic acid accumulates due to which we feel tired.