This resource describes the structure and functions of the cell membrane.

This cellular biology page presents extensive detail on the chemical nature of the cell membrane. Using the Chime plug-in, students can manipulate and study models of the membrane.

This site has information on how facilitated diffusion of ions takes place through proteins, or assemblies of proteins, embedded in the plasma membrane. Includes a helpful diagram.

[Free Registration/Login may be required to access all resource tools.] The cell membrane is semi-permeable. Sometimes molecules need the help of special transport proteins or an input of energy to help them move across it. When an input...

[Free Registration/Login may be required to access all resource tools.] Describes passive transport and diffusion.

This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models. (Requires Java)

[Free Registration/Login may be required to access all resource tools.] Describes facilitated diffusion.

An activity to understand how diffusion is a result of random motion and collisions of particles. With the virtual labs, explore how a drop of food coloring into a glass spreads and how perfume diffuses at different temperatures and...

Explains the processes of osmosis and diffusion using labeled illustrations, discusses how they occur and gives examples.

Moving materials across the cell membrane sometimes requires energy, called active transport. This tutorial covers both primary and secondary active transport with good clear animations.

In this module, students discover how each cell is organized to complete the function of producing and transporting proteins, and how cells relate to homeostasis of the body.

Great overview of cell membranes. The site presents the information as a tutorial with multiple choice questions to guide the learner. Very well designed site on cell membranes.

In this third unit of a Biology course, students learn about cells and cell structure. They compare prokaryotic and eukaryotic cells and learn about the specialized structures in a cell and what their functions are. They will also learn...

This definition and explanation osmosis shows how water diffuses from regions where it is in high concentration to regions where it is in low concentration.

This resource is an article about the cell membrane, and its role in water and solute movement in and out of the cell.

Cell transport can be active or passive. The two forms are described here and their differences highlighted.

The cell membrane is one of the great multi-taskers of biology. It provides structure for the cell, protects cytosolic contents from the environment, and allows cells to act as specialized units. Learn how the membrane functions to...

For an organism to function, substances must move into and out of cells. Three processes contribute to this movement - diffusion, osmosis and active transport. Diffusion is the process by which useful materials and waste products move in...

Practice exercise on facilitated diffusion.

[Free Registration/Login may be required to access all resource tools.] During active transport, molecules move from an area of low concentration to an area of high concentration. This is the opposite of diffusion, and these molecules...

An interactive demonstration where students make observations of the process of diffusion. Students draw and record observations, make predictions, and make comparisons between what they're observing and how a cell membrane works.

[Free Registration/Login may be required to access all resource tools.] The process of molecules moving from an area where there are lots of molecules to an area where there are fewer molecules is known as diffusion. The diffusion of...

Diagrams and animations help you understand the basics of cell membrane structure and function.

Answer five multiple-choice quiz questions about the different types of cellular transport.