1. Engage – what do these molecules have in common?
They are substance/molecules that need to be transported into or out of cells.

2. Learning Objectives

3. Draw a line under last lesson’s work and write today’s title in your book...
18/09/2018
c/w
Cell Transport
Must be able to… describe the terms diffusion, osmosis and active transport
Should be able to… give examples of how each transport mechanism is used in plants and animals
Could be able to… explain the key differences between osmosis, diffusion and active transport.

4. Explain
Diffusion

6. Active Transport Requires energy from respiration
Against concentration gradient
Low to high concentration

7. Osmosis
Movement of water molecules from a high concentration to a low concentration through a partially permeable membrane.

8. Animation of diffusion & osmosis

9. Animation of diffusion, osmosis and active transport

10. Checking understanding
Evaluate
Checking understanding
Describe how perfume smell spreads
Explain why a slice of potato will decrease in mass if it is placed in a concentrated sugar solution
Muscle cells in the leg use up oxygen but are surrounded by a fluid containing a lot of oxygen. Explain why oxygen moves into cells.
Explain why water moves into a plant.
An 8g piece of potato is left in water for an hour. Its mass becomes 8.5g. Calculate the percentage change in mass.

11. Purple pen time! Describe how perfume smell spreads
The particles move from a high concentration from where the perfume was sprayed to a low concentration. This is called diffusion.
2. Explain why a slice of potato will decrease in mass if it is placed in a concentrated sugar solution.
This is because water will move from inside the potato where there is a high concentration to outside the potato where there is a low concentration through a partially permeable membrane. This is called osmosis.

12. Purple pen time!
3. Muscle cells in the leg use up oxygen but are surrounded by a fluid containing a lot of oxygen. Explain why oxygen moves into cells. Oxygen is found in a high concentration in the fluid and in the blood vessels surrounding the cells. It will therefore move from a high concentration to a low concntration. 4. Explain why water moves into a plant. This is because water is found in a high concentration in the soil and it then moves from a high concentration to a low concentration through the root hair cells.

13. Purple pen time!
An 8g piece of potato is left in water for an hour. Its mass becomes 8.5g. Calculate the percentage change in mass.
8.5 – 8.0 = 0.5
= 0.5 / 8.0 x 100
= 6.25%