1. Cell Transport

2. Selectively Permeable
A property or characteristic of the cell membrane.
It can allow some materials to pass through while keeping other materials out.
Ex: allows water and nutrients in; wants to keep toxins out

3. Some things can pass through on their own, some need help, some cannot pass at all.

4. Diffusion
The movement of molecules from a higher concentration (crowded) to a lower concentration (more space)

5. Osmosis The diffusion of water through a cell membrane
Happens when water enters the roots of a plant
Water also moves from a higher concentration to a lower concentration
How do you lower the concentration of water?

6. Osmosis
Normal RBC
RBC in pure distilled water

7. Equilibrium
A state when the molecules are spread out evenly – but remember the molecules are still moving.

8. 2 Types of Transport Across the Cell Membrane
1. Passive Transport
The cell uses NO energy; the molecules don’t need any help to cross the cell membrane
Diffusion
Osmosis

9. 2 Types of Transport Across the Cell Membrane
2. Active Transport
The cell uses energy (from ATP) to move materials across the cell membrane
a transport protein may escort the material
Move from an area of low concentration to high concentration – against the normal direction of diffusion

10. Active Transport