| Characters | Respiration | Combustion |
| 1. Nature of process | Biochemical and stepped. | Physico- chemical and spontaneous. |
| 2. Site of occurrence | Inside the cells. | Not cellular. |
| 3. Control | Biologically controlled | Uncontrolled. |
| 4. Energy release | Energy released in steps. | Energy released simultaneously. |
| 5. Temperature | Remains within limits. | Rises very high. |
| 6. Light | No light is produced. | Light may be produced. |
| 7. Enzymes | Controlled by enzymes. | Not controlled by enzymes. |
| 8. Intermediates | Several intermediates are produced. | No intermediate is produced. |
| 9. ATP formation | Most of the energy is trapped in ATP molecules. | No ATP is formed during combustion. |