Anaerobic respiration:
It is a type of respiration that occurs without oxygen.
The process of respiration that occurs in the absence of oxygen is known as anaerobic respiration.
The process of anaerobic respiration
During this respiration glucose is converted into ethanol.
The general equation of anaerobic respiration is:
Glucose                         Ethanol
Based on the end products and the organism in which it occurs anaerobic respiration is of two types.
  1. Alcoholic fermentation: It occurs in yeast
  2. Lactic acid fermentation: It occurs in bacteria
Production of ethyl alcohol
Lactic acid fermentation
Respiratory quotient (R.Q):
The ratio of volume of carbon dioxide liberated and the volume of oxygen consumed during respiration is known as respiratory quotient.
It is calculated by using the following formula.
Differences between aerobic and anaerobic respiration:
Aerobic respiration
Anaerobic respiration
1.It occurs in the presence of oxygen.It occurs in the absence of oxygen
2.Carbon dioxide, water and ATP are its products.Lactic acid, ethanol and ATP are its products.
It occurs in 3 steps:
  • Glycolysis
  • Kreb's cycle
  • Electron transport chain
It occurs in 3 steps:
  • Glycolysis
  • Fermentation (ethyl alcohol or lactic acid are produced)
Differences between light-dependent and light independent reaction:
Light-dependent reaction
Light independent reaction
1.It is also known as Hill reaction or light reaction.It is also known as dark reaction or biosynthetic pathway or Calvin cycle.
2.These reactions occurs in the thylakoid membranes (Grana) of the chloroplast.These reactions occur in the stroma of the chloroplast.
3. During these reactions the photosynthetic pigments absorb the light energy and convert it into chemical energy such as ATP and \(NADPH_2\). During these reactions \(CO_2\) is reduced into carbohydrates by using the ATP and \(NADPH_2\).
4.These reactions occur in the presence of light.These reactions occur in the absence of light.