Question

Is facilitated diffusion a type of active or passive transport? How is it different from regular diffusion?

Answer 1

The movement of particles from higher concentration to a lower concentration is called diffusion. It is of two types: simple or regular and facilitated diffusion.

Complete answer:
Facilitated diffusion is a form of passive transport. It is called facilitated diffusion because it depends on the help of proteins called transport proteins embedded in the cell membrane.
The diffusing particles move to enter or leave a cell through these proteins because the particles are unable to move directly through the cell membrane.

Simple diffusion	Facilitated diffusion
Carrier molecules are not required.	Carrier molecules are required.
Low speed.	The speed is fast.
Not solute specific.	Solute specific.
ATP not required.	ATP required.
Molecules only move in the direction of concentration gradient.	Molecules can pass both in direction and against the concentration gradient.
It allows the movement of only small and nonpolar molecules.	Large and polar molecules move via facilitated diffusion.

Note: 1)Facilitated diffusion is used by molecules which cannot cross the phospholipid bilayer easily.
2)Channel proteins and carrier proteins help in this process.
3)The electrical nerve impulses travel by facilitated diffusion.
4)It is a selective process.