Rescue Me!

I don't know about 'for dummies' but there are many of 'em out there. This one seems to do a decent job explaining it:

http://www.mun.ca/biology/Osmosis_Diffusion/tutor2.html

Here are a couple with animations that may help:

http://www.biologycorner.com/bio1/diffusion.html#

http://www.wiley.com/legacy/college/boyer/0470003790/animations/membrane_transport/membrane_transport.htm

You can Google this stuff for hours...

Does anyone know of a website for dummies that will solidify the concepts of osmosis and diffusion for me. Even when I think I have a handle on these, the ability to describe them escapes me. I want to understand them, not just have textbook definitions. I'd appreciate any and all help, advice and prayers at this point!

you know what I did? I got out childrens text books, it is a way to really simplify things for you, and from there you can learn more about it. It's not as hard as you might be thinking it is, and this little trick might really help. I have a 5th graders so I have access to these tools, but if you don't you could just pop into a barnes and noble or look at your library. It sounds silly but sometimes what you need to start is the simplest of explanations and then you can build on it.

I am enclosing my AP notes regarding this very topic.

Think of diffusion occurring in an "open" space, like inside a wall like your blood vessels. Diffusion means that if "things" get all clumped up into one side of the "open" space, they will spread out so that things are even throughout that space.

Now, osmosis. First you have to know the difference between a solute and solution.

Let's take salt water for instance. In salt water the solute is the sodium in the water. The solution is the "whole" volume of salt water.

NOW..... with osmotic pressure..... it keeps things (solutes vs. solution) "even" in the space it is in. (Similar to diffusion). The MAIN difference is that with osmosis there is a selectively permeable membrane (this is a fancy way of saying it only lets certain things go through it) in the "middle" and it (osmotic pressure) has to maintain pressure on both sides of the membrane. (Think of a box with a divider in the middle of it making the box into 2 smaller areas within the larger box).

SO, Osmotic pressure works like this.... the water molecules like to keep even amounts of solution (remember this term) on BOTH sides of the membranes. To do this it uses pressure to push water molecules to the side that has MORE solute. Low solute side moves water molecules to side with high amounts of solute. (Concentration gradient).

A & P I (chap. 3) Cellular Form & Function.doc

http://www.amazon.com/Fluids-Electrolytes-Made-Incredibly-Easy/dp/1582555656/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1200959064&sr=8-1

Fluid and Electrolytes made Incredibly Easy had a good review chapter - good luck!