The term respiration was coined by Pepys (1966). Respiration is a biochemical energy-releasing enzymatically controlled process where food is oxidized for step-wise release of energy. During this process, the cell oxidizes the food (glucose) and releases carbon dioxide, water, and energy. This energy is stored in a biomolecule (ATP molecule) and is utilized constantly for carrying out different cellular activities.
Difference Between Aerobic and Anaerobic Respiration:
The following are the points of difference between Aerobic and Anaerobic respiration-
Aerobic respiration takes place in the presence of free oxygen.
Anaerobic respiration takes place in the absence of free oxygen.
There is an exchange of oxygen and carbon dioxide between the cells and their environment.
Respiratory exchange of gases is not involved as oxygen is not absorbed by respiring cells.
The respiratory substrate is completely broken down.
The respiratory substrate is incompletely broken down.
The end products are inorganic.
At least one of the end products is organic. Inorganic substances may or may not be produced.
It produces carbon dioxide.
Carbon dioxide may or may not be produced. Wherever formed, it is produced in a comparatively smaller quantity.
Metabolic water is formed as one of the end products.
Metabolic water is not produced.
One gram mole of glucose gives rise to 38 ATP molecules.
One gram mole of glucose gives rise to 2 ATP molecules.
Aerobic Respiration occurs in cytoplasm and mitochondria.
Anaerobic Respiration occurs only in the cytoplasm.
Aerobic Respiration occurs in four steps- glycolysis, link reaction, TCA or Krebs cycle, and terminal oxidation.
Anaerobic Respiration takes place in two steps- glycolysis and fermentation.
Aerobic Respiration occurs in all living cells of higher organisms.
Anaerobic Respiration is found in fewer organisms, mostly in endoparasites and submerged aquatics.
An electron transport chain is required.
An electron transport chain or system is not required.
Oxygen is the ultimate acceptor of electrons and protons.
Pyruvate or its derivative is the acceptor of electrons and protons.
Energy production in prokaryotes during aerobic respiration is 38 ATPs.
Energy production in eukaryotes during aerobic respiration is 36 ATPs.