1. CELLS
Tonicity

2. Hypotonic
The concentration of solutes in the solution is lower than the concentration of solutes in the cell
Water moves into the cell causing it to swell
In an animal cell, if too much water enters the cell, it may burst (lysis)
In a plant cell, the pressure on the cell wall
increases (turgor)

3. Isotonic
The concentration inside the cell is equal to the concentration outside the cell
There is no net movement of molecules in or out of the cell, so the cell maintains its normal size and shape

4. Hypertonic
The concentration of solutes outside the cell is higher than inside the cell
Water moves out of the cell
In an animal cell, the cell shrinks
In a plant cell, the cell membrane pulls
away from the cell wall (wilts)

5. Cell in Isotonic Solution
10% NaCL 90% H2O
ENVIRONMENT
CELL
NO NET MOVEMENT
10% NaCL
90% H2O
What is the direction of water movement?
Water moves in and out of the cell equally so no net movement of water.

6. Cell in Hypertonic Solution
15% NaCl 85% H2O
ENVIRONMENT
CELL
5% NaCl
95% H2O
What is the direction of water movement?
Water moves out of the cell.

7. Cell in Hypotonic Solution
10% NaCL 90% H2O
ENVIRONMENT
CELL
20% NaCL
80% H2O
What is the direction of water movement?
Water moves into the cell.