1. DIFFUSION & OSMOSIS

2. Cell membranes are permeable (having pores or openings) to water, therefore, the environment the cell is exposed to can have a dramatic effect on the cell.

3. Cell Membranes

5. Plasma membrane

8. Passive Transport
Active Transport

11. DIFFUSION
Molecules move from areas of higher concentrations to areas of lower concentrations

16. Osmosis: the movement of water molecules from an area of high concentration to an area of low concentration.

17. OSMOSIS

19. Isotonic
Isotonic : contains the same concentration inside & outside the cell. Water diffuses into & out of cell at the same rate.

20. Hypotonic
contains a low concentration)
The water diffuses into the cell, causing the cell to swell and possibly explode.
Hypotonic

21. Hypertonic : contains a high concentration The water diffuses out of the cell, causing the cell to shrivel.
Hypertonic

30. Question?
How does the cell membrane know what to let in and what to let out?

31. SELECTIVE PERMEABILITY

32. SELECTIVE PERMEABILITY

34. Passive & Active Transport
You should know & be able to explain the following points:
Osmosis
Diffusion
Membrane structure
Selective Permeability
Passive & Active Transport