| S.N. | Outer mitochondrial membrane | Inner mitochondrial membrane |
| 1. | It is smooth, having much less surface area. | It is unfolded to form cristae, hence having very large surface area. |
| 2. | It is freely permeable unlike most biological membranes. | It is semipermeable like most biological membranes. |
| 3. | It consists of 50% proteins and 50% lipids. | It consists of 80% proteins and 20% lipids. |
| 4. | Its lipids include a large amount of cholesterol and no cardiolipin. | Its lipids include cardiolipin and virtually no cholesterol. |
| 5. | Its proteins include porins that form channels for free movement of molecules across the outer membrane. | Its proteins include permeases that actively transport desired molecules across the inner membrane. |
| 6. | It doesn’t consist of much enzymes. | It is rich in enzymes. |
| 7. | It lacks electron transport system. | It bears electron transport system. |
| 8. | It is contact with the cytoplasm. | It is in contact with the matrix. |