What is the difference between Respiration and Combustion ?



Energy is also released in the form of heat and light when we burn compounds in air and oxidized them. During combustion or burning, the oxygen of the air combines with the compound and releases energy in one step. In cells, during respiration, energy is released in a series of steps and the oxidation is slower. Respiration represents controlled combustion. The differences between respiration and combustion are given below.


1. It takes place in living cells only.

2. It is carried out with the help of various enzymes.

3. The oxidation of food and the liberation of energy occur in a step-wise manner.

4. It occurs at the body temperature of the organism.

5. 60% of energy escapes as body heat and 40% of energy is packaged directly into new chemical energy (ATP).


1. It does not take place in the living cell.

2. Enzymes are not involved in this process.

3. The substances are oxidized Spontaneously with sudden release of energy.

4. Sudden release of energy generates high temperature of a fire.

5. Energy released in combustion is dissipated as heat and to some extent as light.