1. B3 – Exchange of materials
What are diffusion, osmosis and active transport?
Starter:
A chip shop owner prepares his chips earlier in the day for the evening rush.
He stores them in water until he needs to use them.
What effect will this have on the chips?

2. Glossary
Osmosis: the net movement of water from a high concentration of water to a low concentration of water.
Diffusion: the net movement of particles from a high concentration to a low concentration.
Active Transport: the movement of substances against a concentration gradient.

3. Osmosis Demo – visking tubing with sugar solution in. Sugar solution
Strong Sugar Solution
water

4. Osmosis and Diffusion Osmosis is the movement of WATER
Diffusion is the movement of solutes.
Key point: NO energy is needed.

5. What is a Concentration Gradient?
Hills and graphs have gradients
1) which is the steepest gradient?
2) which move up a gradient and which move down a gradient?

6. moving down a concentration gradient
Which way will the particles move?

7. Active transport This DOES Require energy
Particles move against a concentration gradient.
The energy is needed to make “pumps” move particles the wrong way.
E.g. glucose from the intestine into the blood

8. Active Transport

9. moving UP or against a concentration gradient
ENERGY
The particles can move up the concentration gradient if energy is used
This is active transport

10. Active Transport
Active Transport

11. Active transport in plants

12. Active Transport
Active transport occurs across semi permeable membranes and moves particles from a low concentration to a higher concentration. This is against the concentration gradient.
Transport or carrier proteins are needed to get these molecules into the cells and these use energy.
Cells that do active transport contain large numbers of mitochondria.
Q: Where does the energy come from?
Q: What do mitochondria do?

13. Active Transport
Inside of cell Outside of cell
ATP
ADP P

14. Tasks Use the information to fill in the Venn diagram.
To easy? Write a comparison of the 3 modes of transport.

15. Complete the past paper questions

16. Lumen of small Intestine
Na+ high concentration
Glucose
Lumen of small Intestine
Co Transport
Na+ low concentration
Glucose
Epithelial Cell K+
Active Transport
Facilitated Diffusion
Blood Capillary
Glucose K+

17. Plenary
Make a list of similarities and differences between active transport and diffusion

18. Wordsearch
Wordsearch