1. Osmosis

2. The cell membrane is selectively permeable
The cell membrane is selectively permeable. This means that only certain things are allowed to go through it, like food and oxygen.

3. Things move in and out of the cell through the process of diffusion.
They move from an area of high concentration to an area of low concentration.

4. The most important substance to go through the cell membrane is water
The most important substance to go through the cell membrane is water. Cytoplasm is 80% water.
Osmosis is a special type of diffusion where water (and only water) moves from high to low concentration.

5. Fresh water will always move toward salty water
Fresh water will always move toward salty water. In other words, water moves from an area of high purity to an area of low purity.

6. Trout
If we place a trout in fresh water, what does the trout’s cells look like? 
Equal concentration inside and outside the cell cell is happy!!

7. Trout
If we place a trout in saltwater (ocean), what happens to the trout cells?
Higher salt concentration outside the cell water moves out of the cell.
If we place a trout in saltwater (ocean), what happens to the trout cells?
Higher salt concentration outside the cell water moves out of the cell.
Cell Shrinks!
Cell Shrinks!

10. Shark
If we place a shark in fresh water, what happens to the shark’s cells?
More salt inside cell water rushes in to dilute salt.
CELL BURSTS!

13. Shark
If we place a shark in saltwater (ocean), what do the shark’s cells look like? 
Equal inside and outside of cellHappy!

14. Sources
red blood cells
bursting red blood cell
turgid cells
osmosis diagram