1. Osmosis in Cells Some fab real time osmosis videos to set the mood!

2. Group Starter Activity Mr and Mrs Martinez went on holiday to Acapulco for a few days. When they came back their favourite plant looked like this! Explain the changes in terms of water movement 5 days ago Today

4. Plants- Water moving in We say that the cell is turgid . Water moves into a plant cell. The cell wall stops the cell from bursting. Turgid cell. Vacuole is filling all the space and pushing against cell wall This is useful as it gives plant stems support

5. Cell turgor pressure

6. Plants- Water moving out If a lot of water leaves the cell, the cytoplasm starts to peel away from the cell wall and we say the cell has undergone plasmolysis . When water moves out of the plant cell vacuole, by osmosis, it becomes flaccid Flaccid cell. Vacuole is much smaller and taking up less space

7. Plasmolysis

8. Osmosis in Plant Cells Low water concentration outside the cell (ie concentrated solution outside) High water concentration outside the cell (ie pure water or dilute solution outside) Equal water concentrations inside & out (ie equal solute concentrations inside & out)

9. Animals- Water moving in Animal cells have no cell wall to stop the swelling, just a flexible cell membrane. haemolysed turgid then burst normal If an animal cells are put in pure water (HWC) they take in water by osmosis until they burst .

10. Animals- Water moving out haemolysed http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm normal If an animal cells are put in a concentrated solution (LWC) they lose water by osmosis until they become shrunken or haemolysed .

12. Now try your osmosis practice problems!