1. Bell Work Find your quizzes from yesterday (put in notebook).
January 18, 2009
Bell Work
Find your quizzes from yesterday (put in notebook).
Take out your vocab.

2. Today’s Learning Goals
1. A) Describe the process of diffusion.
1. B) Explain how osmosis occurs.
1. C) Compare and contrast osmosis and diffusion.

3. X x x
x x
X x x
X x x x x x x x
xxxx x x xxxx x
X x x x x x x x x

4. Diffusion Molecules – Building blocks of matter. Diffusion:
The movement of molecules from an area of high to an area of low concentration.
•Ex: Perfume Diffusing through a room. •Ex: Dye diffusing through water

5. What speeds up the rate of diffusion?
Add heat
Heat Energy- Causes molecules to vibrate

6. What is a cell membrane? A thin envelope that surrounds a cell
Lets things in & out.
A membrane can be:
Impermeable --- Substances cannot pass thru
Permeable --- Substances can freely pass thru
Semi-Permeable ---- Allows some substances

7. Osmosis
Osmosis: The diffusion of water across a semi-permeable membrane.
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* In diffusions/osmosis, molecules always move toward a low concentration

8. Osmosis What is the concentration of the
water compared to that of the cell?
A. Equal Concentrations
B. Water is Low Concentration
C. Water is High Concentration
A B C

9. Diffusion/Osmosis Lab