1. Ziplocs
Farts
Teabags
Cells?
Prune hands
Balloons
Cologne

2. or Osmosis and Diffusion
Farts, Ziplocs, Teabags, Cologne,
Balloons, Prune hands, and… Cells?
or Osmosis and Diffusion

3. How substances move IN and OUT of cells…
We will be learning about . . .
The Semipermeable Cell Membrane
Diffusion
Osmosis

4. An odour released at on end of the room is quickly detected in the far corner. Why? How?

5. Diffusion is the movement of particles from an area of high concentration to an area of low concentration. It is a random process that eventually “evens out”
What do you notice about the distribution of each coloured particle?

6. How does the tea spread through the glass?
Why don’t the tea leaves diffuse?

7. start

8. after ~20 mins.

9. The tea bag is selectively permeable
The tea bag is selectively permeable. That is, they allow some particles to pass through it, but not others.
The cell membrane is selectively permeable. That is, it allows some particles to pass through it, but not others.

11. Unicellular organisms obtain water by osmosis.

12. Water is essential to the survival of a cell
Water is essential to the survival of a cell. Because it so important, diffusion of water across a selectively permeable membrane is given a special name.
Osmosis is the diffusion of water across a selectively permeable membrane.

13. Important things to remember (and almost always got wrong by students)
When there is a high concentration of a solute e.g. salt, there is a low concentration of water
When there is a low concentration of the solute, there is a high concentration of water.

14. Inside cell Outside cell
Task 1 -
Label the following in the diagram
Pore in cell membrane
Semipermeable Cell membrane
Water molecules
Solvent molecules
High concentration of water
Low concentration of water
High concentration of solute
Low concentration of solute
Task 2-
Draw an arrow on your diagram to show the direction of the movement of water molecules.
In your own words explain why this has happened.

15. Remember…
Salt sucks!!