Author: Nathan Lampson

This lesson will explain how substances move across a cell membrane through the process of diffusion as well as discuss why this process is important in our bodies.

See More
Try a College Course Free

Sophia’s self-paced online courses are a great way to save time and money as you earn credits eligible for transfer to over 2,000 colleges and universities.*

Begin Free Trial
No credit card required

28 Sophia partners guarantee credit transfer.

263 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 25 of Sophia’s online courses. More than 2,000 colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.

Terms to Know
Concentration Gradient

The difference in concentration of a substance between two areas


Movement of molecules from an area of high concentration to an area of low concentration

Passive Transport

The movement of molecules across a membrane without the use of energy