1. 1
Osmosis

2. Water and other small molecules that do not dissolve in lipids diffuse through openings formed by proteins that go through the entire membrane.
Diffusion of water through a membrane is called osmosis.

3. Osmosis
Since water makes up % of a living cell, its movement in and out is of vital importance.
The cell has no control over osmosis. Osmosis will end when equilibrium is reached.
The water concentration is determined by the concentration of solutes in the water.

5. Isotonic Solution concentration of solutes equal in and out of cell
Iso = same

6. Hypotonic Solution concentration of solutes outside is lower
more water, less solutes
ex: distilled water
hypo = under

7. Hypertonic Solution concentration of solutes outside is higher
less water, more solutes
ex: saltwater
hyper = above

8. What is the effect of hypotonic solutions on cells?

10. Cells in hypotonic solutions take in water.
In plant cells, the cell wall can take the increased pressure and turgor results.
The plant cells are stiff.

12. Animal cells can use excretion or contractile vacuoles (found in unicellular organisms) to keep from bursting - cytolysis.
cyte = cell
- lysis = to burst

13. When cells are put in distilled water and burst due to cytolysis the membranes and contents can be separated by a centrifuge for detailed study.

14. What is the effect of hypertonic solutions on cells?

16. Cells in hypertonic solutions lose water
Cells in hypertonic solutions lose water. This causes cells to shrink - plasmolysis.

17. Onion cells in saltwater
Normal onion cells

18. Elodea leaf in saltwater

19. Elodea cell in a hypotonic solution
Elodea cell in a hypertonic solution
Water
Water

20. If humans drink seawater, their cells lose more water than they take in.

21. Animal
Cells

23. Plant Cells

24. Since osmosis and diffusion take place without any use of energy by the cell, they are forms of passive transport.

26. For your entertainment…