Following Table gives a comparison of the different transport mechanisms.
| Property | Simple Diffusion | Facilitated Transport | Active Transport |
| Requires special membrane proteins | No | Yes | Yes |
| Highly selective | No | Yes | Yes |
| Transport saturates | No | Yes | Yes |
| Uphill transport | No | No | Yes |
| Requires ATP energy | No | No | Yes |
Proteins in the membrane are responsible for facilitated diffusion and active transport and hence show common characterstics of being highly selective; they are liable to saturate, respond to inhibitors and are under hormonal regulation.
But diffusion whether facilitated or not – take place only along a gradient and do not use energy.