1. Diffusion and Osmosis
Biology

2. Ask Yourself What is moving? If molecules move: its diffusion
Diffusion moves molecules from an area of high concentration to an area of low concentration.
NO ENERGY REQUIRED!

3. Diffusion Simulation

4. You practice
Complete the Part I Of the handout on diffusion (3 minutes)

5. OSMOSIS Water is moving!!!! To the side with more solute!!!!
NO ENERGY REQUIRED!!!

6. Solute vs. Solvent
Solute: molecule that dissolves in solution. Ex. Sugar, salt
Solvent: Molecule that allows the solute to dissolve. Ex. Solvent
Ex. In Kool-Aid, sugar and the kool-Aid powder are the solutes. Water is the solvent.
Water is the universal solvent!

8. Osmotic Solutions
There are three types of solutions into which cells may be placed: Hypertonic Solutions Hypotonic Solutions Isotonic Solutions

9. Hypertonic
Hyper= means high Hypertonic Solutions: Higher concentration of solute Notice: This cell has been placed into a solution with many solute molecules.

10. Hypertonic Solutions
Where does water move in osmosis? To the side with more molecules!!!!!!!!! So where will it move? Outside the cell! This will cause the cell to SHRINK!!!!!

11. Hypertonic Solutions

12. Hypotonic HYPO means LOW
Hypotonic solutions have lower concentrations of solute compared to the inside of the cell

13. Hypotonic Solutions Where does the water move in Osmosis?
To the side with more solute molecules.
Water will move inside the cell and cause it to SWELL!!!!
Cells that swell up too much can burst open

14. Isotonic Solution Iso means the same
Cells that are put into isotonic solutions have the same concentrations. They are at equilibrium.

15. Which kind of solution
Cells are placed in a beaker. The concentration of solute (salt) molecules inside the beaker is 30%. The concentration of solute molecules inside the cell is 8% . What type of solution is this?
A.) Hypertonic
B.) Hypotonic
C.) Isotonic

16. A cell is placed in a solution for an hour
A cell is placed in a solution for an hour. After the hour time period, the cell is still the same size as it was when it was first put into the solution. This cell was put into a(n)
A.) Hypertonic Solution
B.)Hypotonic Solution
C.) Isotonic Solution

17. A cell shrinks. It must have been placed into a(n)
A.) Hypotonic
B.) Hypertonic
C.) Isotonic Solution

18. Red Blood Cells