1. DIFFUSION / OSMOSIS

2. What does the prefix ‘homo’ mean? Same

3. HOMEOSTASIS Homeostasis (aka Homoeostasis): the tendency of a system to STAY THE SAME Our body is an example of a system

4. There are two ways that homeostasis can be maintained: – Diffusion – Osmosis

5. OSMOSIS Osmosis is the movement of WATER from high to low concentration.

8. Membranes (barriers) can be permeable  Permeable (def.): allowing things (such as liquid or solids) to pass through

9. What does the word ‘selective’ mean? *Think of charter schools that are described as selectively enrolled students So what does selective permeability mean?

10. SELECTIVE PERMEABILITY Selective Permeability: a PARTIALLY selective membrane that allows only CERTAIN things to go through

11. DIFFUSION Diffusion is movement of solid, gases, and other substances molecules (solutes) from high to low concentration.

12. PRACTICE/PREDICTION

14. 3 TYPES OF CONCENTRATION Hypertonic Hypotonic Isotonic Hyper = More Hypo = Less Iso = Same

15. concentration of solute outside of the cell is EQUAL to the concentration of solute inside the cell. H2OH2O H2OH2O Water Molecule Dissolved Molecule ISOTONIC SOLUTION

17. HYPOTONIC SOLUTION Concentration of solute is LOWER (higher water concentration) outside of the cell than the concentration of solute inside the cell. H2OH2O H2OH2O Water Molecule Dissolved Molecule

18. In a HYPOtonic solution - The cell swells because more water goes in the cell. Less solutes outside of the cell, high concentration of solutes in the cell, so water moves in.

20. HYPERTONIC SOLUTION Concentration of solute is HIGHER (water concentration is lower) outside of the cell than the Concentration of solute inside of the cell H2OH2O H2OH2O Water molecule Dissolved molecule

22. In a HYPERtonic solution - The cell shrinks because water leaves the cell. High concentration of solids on the outside of the cell, so the cell loses water and shrinks.

23. What type of solution is this Hypo-, Hyper- or Iso- tonic? Which way will the water move?

24. Hypotonic Water moves INTO the cell

25. What type of solution is this Hypo-, Hyper- or Iso- tonic? Which way will the water move?

26. Isotonic Water moves at an EQUAL rate into and out ofthe cell

27. What type of solution is this Hypo-, Hyper- or Iso- tonic? Which way will the water move?

28. Hypertonic Water moves OUT of the cell

30. water Cell SWELLS Cell stays the SAME Cell Shrinks

32. ANIMAL CELL PLANT CELL IsotonicHypotonicHypertonic IsotonicHypotonicHypertonic