Difference between “Respiration” and “Combustion” – Explained!

Respiration:

1. Respiration being a biological process occurs in living cells.

2. Respiration is the slow oxidation of organic substances (glucose) which results in stepwise release of energy.

3. The heat evolved during respiration is stepwise; hence it does not harm the cells and organelles.

4. The heat energy evolved is either made available to the cells or is stored as chemical energy in the form of ATP.

5. Respiration reactions are catalyzed by enzymes.

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Combustion:

1. Combustion is a non-biological process and hence it is non-cellular.

2. Combustion is a rapid oxidation of a substrate (like coal) and results in the release of the energy abruptly.

3. The heat evolved during combustion is abrupt hence it raises the temperature which results in fire.

4. The heat energy evolved is made use of at the time of evolution and is not stored.

5. Enzymes are not used in combustion.