1. Movement Across Cell Membranes
Grade 8 Science
Ms. Nilmalgoda

2. Activity: The Party Farter
Diffusion
Activity: The Party Farter

3. Diffusion

4. Diffusion Across a Membrane

5. Diffusion Across a Membrane

6. Diffusion Across a Membrane
More Oxygen OUTSIDE the Cell
Oxygen Diffuses INTO the Cell

7. Quick review of some terms …
Osmosis
Quick review of some terms …

8. PARTS OF A SOLUTION SOLUTE SOLVENT SOLUTION
Substance that dissolves in a solvent (the part that is mixed in).
SOLVENT
Substance that dissolves a solute.
SOLUTION
The result of a solute dissolved in a solvent; the resulting mixture.

9. PARTS OF A SOLUTION

10. Osmosis
Specifically, the movement of WATER across a semi-permeable membrane.
Water moves from a dilute solution (HIGH concentration of water) to a concentrated solution (LOW concentration of water)
With OSMOSIS we are focusing on the movement of the SOLVENT (whereas with DIFFUSION, we are focusing on the movement of the SOLUTE)

11. Osmosis

12. Osmosis

13. Videos! Diffusion: Osmosis:
Osmosis:

14. Gummy Bear Osmosis

15. Active Transport
Movement across a membrane AGAINST concentration gradient.
In other words, from LOW concentration to HIGH concentration.
REQUIRES ENERGY!

16. Active Transport

17. Active Transport is like a ...
... Japanese subway station?

18. Animation of Diffusion, Osmosis, and Active Transport

19. Reminder: The Particle Theory
All matter is made of particles.
Particles are constantly in motion (moving). Adding heat or energy will make particles move faster.
There are attractive forces between particles. There is also space between particles. 
All particles of one substance are the same. Different substances are made of different particles.