Facilitated Diffusion

What is facilitated diffusion?

A passive process that uses specific protein carriers or channels to transport charged particles and polar molecules across the membrane.

What types of molecules are transported by facilitated diffusion?

Charged particles, polar molecules, and large molecules that are too big to cross the membrane by simple diffusion.

What is the direction of movement in facilitated diffusion?

From a region of high concentration to a region of lower concentration.

What is co-transport?

The process where two different particles are transported through the same protein at the same time.

Give an example of co-transport.

Glucose and Na+ are transported into cells together.

What factors affect the rate of facilitated diffusion?

The rate of facilitated diffusion is dependent on temperature and the number of protein carriers.

How does the number of protein carriers affect the rate of facilitated diffusion?

As the number of protein carriers limits the rate of diffusion, a maximum rate is reached when all carriers are in use (saturated).