1. UNDERSTANDING THE CELL MEMBRANE
CELL (EGG) INQUIRY LAB
UNDERSTANDING
THE CELL MEMBRANE

2. Success Criteria Learning Targets
Obtain information to understand osmosis & diffusion across cell membranes
Prepare for the “Naked Egg” Lab to investigate the affects of different chemicals on cells

3. Video of Experiment

4. Initial Thoughts Why did one egg shrink and the other grow?
How do sponges work?
Why do hospitals use rubber gloves and not cloth gloves?

7. RESEARCH Eggs are cells, but big ones!
Egg Anatomy
Eggs are cells, but big ones!
Most of a cell’s cytoplasm is water!
Cells have a cell membrane that controls what goes in and out.

8. Phet Simulation Diffusion & Osmosis Phet Simulation Link
Use the blue diamonds to represent water and the green dots to represent salt
Add 20 of each to one side and only 20 blue diamonds to the other side
Add 2 blue open channels and 2 green open channels
What do you think will happen? Why?
Turn on the data graphs & watch their levels.
What do you notice?
What happens after 5 minutes?
COMPLETE YOUR MIDDLE CHECK

9. Diffusion, & Osmosis
Diffusion Osmosis and Dialysis
Water moves from where there is A LOT to where there is LESS (this is called OSMOSIS)
Some small molecules (like Water & Oxygen) can go across freely; other things need “Help” getting across.

10. RESOURCES FOR UNDERSTANDING Cell membranes are “Semi-permeable” (Only some things can pass through. Small molecules cross easily but large molecules cannot)
DIFFUSION
OSMOSIS
tch?v=Xxp6oponwkg
tch?v=S_Y__0q0SOU
DEFINITION:
When water moves from an area of high concentration to an area of low concentration
Can happen across cell membranes
tch?v=eQsAzXr0UCU
tch?v=jTDATlaBV-o
DEFINITION:
Similar to diffusion, BUT it’s the movement of water molecules from an area of low concentration to an area of high solute concentration (example salt water or sugar water).

11. Preparing for the Lab
You should have basic understanding of Osmosis, Diffusion, and Semi-Permeable Membranes.
You should have a lot of notes to refer to in case you feel stuck.
*Complete your end check.