A tutorial about the function of the cell membrane as a selective barrier that moves material into and out of the cell to maintain homeostasis.

A narrated tutorial describing the three different kinds of cellular transport: diffusion, osmosis, and facilitated diffusion. Includes descriptive illustrations, analogies, and examples. [13:28]

Resource offers a great explanation and animation of the processes of active and passive transport across cell membranes.

Hank describes how cells regulate their contents and communicate with one another via mechanisms within the cell membrane. [11:44]

This lesson introduces the process of active transport, explaining that it is a form of transport that requires energy, and moves molecules against their concentration gradient. It is 3 of 4 in the series titled "Active Transport."