1. Define the following word: Cell

3. Typical Animal Cell Cytoplasm Nucleus Cell membrane

5. Cells forming tissues Bone cells Nerve cells Cardiac muscle cells

8. Typical Plant Cell Cytoplasm Nucleus Cell membrane Sap vacuole Cell Wall Chloroplast

9. Cell Structure and Function Contains a green chemical called chlorophyll. This green chemical absorbs sunlight to carry out photosynthesis to make food Chloroplast Controls the water content of the plant cell Sap Vacuole Rigid firm coating around the plant cell. It helps to keep the cell shape Cell wall Controls substances that enter and exit the cell, e.g. oxygen, carbon dioxide and food Membrane Jelly like fluid which is the site of chemical reactions in the cell Cytoplasm Control centre of the cell. Contains information which controls everything that goes on in the cell Nucleus Function Structure

10. Looking at Plant Cells Pond weed cells Plant leaf cells packed with chloroplasts

17. Yeast - Unicellular fungus - Cell is dividing - Ferment sugars (used in brewing and bread making) These circles are formed when the cell divides. The new cell ‘ buds off’ and leaves a scar.

20. The discovery of Sir Alexander Fleming! ANTIBIOTICS Fungus Bacteria

22. Yoghurt Making Lactose Lactic acid Bacteria Sugar found in milk Reduces pH of milk causing it to clot (thicken) Bacteria convert lactose into lactic acid

23. What substances need to get into and out of cells? How do they do this?

26. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html Animation of diffusion Click on address to view

27. Food molecules Oxygen molecules Carbon dioxide molecules Diffusion in or out of a living cell

29. OSMOSIS is the special diffusion of WATER from a HIGH WATER concentration to a LOW WATER concentration through a SELECTIVELY PERMEABLE MEMBRANE A membrane which is selectively permeable allows certain molecules to pass through but not others.

30. Membrane fully permeable to small molecules e.g. water Membrane slowly permeable to larger molecules e.g. sugar Membrane is not permeable to huge molecules e.g. starch Selectively permeable membrane Nucleus Cytoplasm

31. Concentration Gradient 99% water 1% sugar 95% water 5% sugar Higher concentration of water Lower concentration of water

32. Water moves down a concentration gradient by OSMOSIS from high to low concentration Lower concentration of water Higher concentration of water Water molecule Sugar molecule Selectively permeable membrane

33. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html Osmosis Animation Click on address to view

35. Water Concentrations A dilute sugar solution has a high water concentration A concentrated solutions has a low water concentration Water moves in or out of a cell depending on whether the water concentration outside the cell is higher or lower than the water concentration inside the cell

36. A HYPOTONIC solution has a higher water concentration than inside the cell A HYPERTONIC solution has a lower water concentration than inside the cell An ISOTONIC solution has a water concentration equal to the water concentration in the cell