1. osmosis & tonicity
Pg.
EQ: How do I correctly analyze the movement of water across a membrane?

3. parts of a solution Solute – the solid part that has been dissolved
Solvent – the liquid that the solute is dissolved in
Ex: Kool-Aid
Solute:
the Kool-Aid powder
Solvent:
the water

4. hypertonic solutions A HYPERtonic solution has:
MORE solute (molecules)
less solvent (liquid)
Than another solution
Another way to think about it is this solution has LESS WATER than another solution

5. which solution is hypertonic?
Solution A: 25% salt, 75% water Solution B: 35% salt, 65% water Discuss your choice with your elbow partner (Hint: ID the solute & solvent) Solution B is hypertonic to solution A because B had 65% solvent and A had 75% solvent, and a hypertonic solution is one with less solvent than another solution.

6. what happens if you put a cell in a hypertonic solution?
Where is there more solute?
Where is there more solvent?
Which solution is hypertonic?
How does water move?
Higher Solute
Lower Solvent
hypertonic
Lower Solute
Higher Solvent
Solute

7. The water moves through the semipermeable membrane from high concentration to low concentration, so it moves outside the cell. The water is trying to reach equilibrium – it wants the same amount of water inside & outside the cell.
This movement of water causes the cell to shrink, which is called crenation.

8. If a solution is hypertonic, it has MORE ___________ and less ____________ than another solution.
solute
solvent

9. hypotonic solutions A HYPOtonic solution has: MORE solvent (liquid)
less solute (molecules)
Than another solution
Another way to think about it is this solution has MORE WATER than another solution

10. which solution is hypotonic?
Solution A: 30% salt, 70% water Solution B: 55% salt, 45% water Discuss your choice with your elbow partner (Hint: ID the solute & solvent) Solution A is hypotonic to solution B because A had 70% solvent and B had 45% solvent, and a hypotonic solution is one with more solvent than another solution.

11. what happens if you put a cell in a hypotonic solution?
Lower Solute
Higher Solvent
Where is there more solute?
Where is there more solvent?
Which solution is hypertonic?
Which solution is hypotonic?
How does water move?
hypertonic
hypotonic
Higher Solute
Lower Solvent
Solute

12. The water moves through the semipermeable membrane from high concentration to low concentration, so it moves inside the cell. The water is trying to reach equilibrium – it wants the same amount of water inside & outside the cell.
This movement of water causes the cell to get bigger. The cell may continue to take on water until it bursts, which is called cytolysis

13. If a solution is hypotonic, it has MORE ___________ and less ____________ than another solution.
solvent
solute

14. This movement of water will not change the cell.
isotonic solutions
An isotonic solution has equal concentrations of solute and solvent. Water moves in and out of the cell at the same rate, so there is no net movement of water.
This movement of water will not change the cell.

15. further questions…
What kind of solution would cause a plant cell to wilt?
What kind of solution was the vinegar for your egg? How do you know?
What kind of solution was the syrup for your egg? How do you know?
What kind of solution was the water for the egg? How do you know?