Simple Diffusion:

* No energy required. This is the movement of molecules from an area of high concentration to an area of low concentration. It relies solely on the random motion of molecules and doesn't need any energy input from the cell.

Facilitated Diffusion:

* No direct energy required, but still indirectly depends on cell energy. Facilitated diffusion uses transport proteins to help molecules cross the cell membrane. While the transport proteins themselves don't directly consume energy, their synthesis and maintenance require the cell to expend energy.

Active Transport:

* Yes, energy is required. Active transport moves molecules against their concentration gradient (from low to high concentration). This requires the cell to expend energy, usually in the form of ATP, to power specific transport proteins.

In summary:

* Simple diffusion: No energy required from the cell.

* Facilitated diffusion: No direct energy required, but indirectly depends on cell energy for protein maintenance.

* Active transport: Requires energy from the cell.

Let me know if you have any more questions about diffusion!