1. Aim What is Osmosis?

2. Water
Water can readily pass through a cell membrane even though many other particles can not.

3. Semi -permeable
When a membrane allows some particles to pass across them but others cannot
Selective permeable

4. Osmosis
The diffusion of water through a semi- permeable membrane

5. Water equilibrium
For organisms to survive they must balance the intake and loss of water

6. Water will move across a membrane towards salt or sugar
Movement of Water
Water will move across a membrane towards salt or sugar
Salt sucks

7. Isotonic
When the concentration water is equal inside and outside of cell
Equilibrium is reached

8. Plant Cells In contact with fresh water Water moves in
Rigid cell walls prevent it from expanding or bursting

9. Bacteria in Fresh Water
Water will tend to move into cell
Uses ATP energy in active transport to pump water out

10. An investigation was set up to study the movement of water through a membrane. The results are shown in the diagram below.
Based on these results, which statement correctly predicts what will happen to red blood cells when they are placed in a beaker containing a water solution in which the salt concentration is much higher than the salt concentration in the red blood cells?
The red blood cells will absorb water and increase in size.
The red blood cells will lose water and decrease in size.
The red blood cells will first absorb water, then lose water and maintain their normal size.
The red blood cells will first lose water, then absorb water, and finally double in size

11. A red onion cell has undergone a change, as represented in the diagram below.
This change is most likely due to the cell being placed in
distilled water
light
salt water
darkness

12. The diagram below represents a plant cell in tap water as seen with a compound light microscope
Which diagram best represents the appearance of the cell after it has been placed in a 15% salt solution for two minutes?