1. Aim: How does Osmosis and Diffusion compare?

2. What is the diffusion of water called?
Osmosis

3. OSMOSIS
The movement of water from an area of high concentration to an area of less concentration.

4. What is meant by concentration?
The amount of solute!
Solvent: The liquid (ex. Water)
Solute: The solid added to the liquid (ex. salt/sugar)
Distilled water
100% pure water

5. *Solute + Solvent = Solution

6. Solution: A mixture of the dissolved material
( solute ) & the dissolving agent ( solvent ).
Ex. sugar (solute) dissolved in water (solvent).

7. Concentration Differences:
1) A 90% salt solution vs. a 20% salt solution
Which solution has more salt particles?
The 90% salt solution
Which solution has more water molecules?
The 20% salt solution
2) A 60% salt solution vs. 80% salt solution?
The 60% salt solution = more water
The 80% salt solution = more salt

8. Which container has a greater concentration of water molecules?
= Solute (salt)
= Solvent (water)
Which container has a greater concentration of solute molecules?

9. Selectively Permeable
In which direction is osmosis going to occur?
= Solute (sugar)
= Solvent (water)
Selectively Permeable

10. Why does this happen?
OSMOSIS

11. Why are the water molecules diffusing to the left?
Water molecules are red

12. The water is moving from an area of high to low!

13. Why does water go in and out of the cell?
If solute is equal, then so is water amount SO
molecules still move back and forth!
To maintain DYNAMIC EQUILIBRIUM

14. What happens to an animal cell if it is surrounded by a low concentration of water?
The Cell will shrink!! Salt sucks!!!!

15. What happens to an animal cell if it is surrounded by a high concentration of water?
The Cell will swell or burst!

16. In which direction will osmosis happen?
H2O

17. How is osmosis a form of passive transport?
Osmosis is the movement of water from an area of high concentration to an area of low concentration. No ATP needed.

18. Practice Questions:
1. A cell containing 98% water in its cytoplasm is placed in a 20% salt solution. What will happen to the cell?
The 90% salt solution
2. What will happen to a cell if it is placed into a concentrated salt solution?
The cell will shrink ( salt sucks).
3. What will happen if a cell is placed in distilled
water?
The cell would burst, because inside the cell has a higher solute concentration than outside.