Diffusion

Hi all,

Today we examined the diffusion of dye in model cells in beaker environments.  We applied the definition of diffusion - the passive movement of molecules from areas of high concentration to areas of low concentration in order to reach equilibrium - to our model cells in their beaker homes.  Additionally, R4 devised a method to determine the rate of temperature on diffusion, and discovered that heat increases the rate of the diffusion of dye.  This makes sense, since diffusion is essentially the movement of molecules, and heat makes molecules move faster.

Here are some helpful animations about diffusion that reveal it's molecular nature.  The second one we will use in class tomorrow:

How Diffusion Works
Perfume Diffusion Simulator

Check these out! They are very helpful at visualizing the molecular level.

Homework
Tomorrow, we are going to examine the structure of the cell membrane to see how it manages to be both a barrier and a window, selectively letting some molecules in and keeping others out.  In preparation for the activity tomorrow, please pre-read pages 84-86 in your textbook about the cell membrane.

Thanks,
Mr. Hill