10 Difference between Cellular Respiration and Photosynthesis

Respiration is a complex process which includes absorption of oxygen, conversion of complex substance like carbohydrates to carbon dioxide and water with release of energy as ATP to drive all cellular activities and as a result there is loss of weight. Where as in photosynthesis complex carbohydrates are built up from simpler substances like carbon dioxide and water with the release of oxygen. Thus respiration is altogether is a reverse process of photosynthesis.

Respiration vs Photosynthesis
Respiration vs Photosynthesis
 It takes place in all the living cells, both green(Chlorophyllated) and non green
 It takes place only in chlorophyllous cells
 It occurs in light and dark, both conditions
 It occurs only in light
  • Glycolysis: in cytoplasm
  • Citric acid cycle or Krebs cycle: mitochondrial matrix
  • Electron transport chain and oxidative phosphorylation: in inner mitochondrial membrane
  • Light reaction: grana of chloroplast
  • Dark reaction or calvin cycle or CO2 fixation: stroma of chloroplast
  • Water splitting complex or photolysis: thylakoid lumen
 Oxygen is utilized and carbon dioxide and water are formed.
C6H12O6 + 6O2-> 6CO2 + 6 H2O+ energy
 Carbon dioxide and water are used while oxygen is evolved.
6CO2 + 12H2O -> C6H12O6 + 6H2O+ 6O2
 It is a catabolic process and includes the destruction of stored food
 It is an anabolic process and includes the manufacture food
 Oxygen is absorbed in the process
 Oxygen is liberated
 Carbohydrates are oxidised
 Carbohydrates are synthesised
 Energy is released during respiration and hence it is an exothermic process.
 Energy is stored during this process and hence it is an endothermic process.
 Energy is liberated in the form of ATP.
 Light energy is stored in the form of glucose or chemical energy.
 Dry weight of plants decreases
 Dry weight of plants increases
 Oxidative phosphorylation occurs
 Photophosphorylation occurs
During the process, potential energy is converted to kinetic energy.
Light energy is converted into potential energy