1. The Cell Membrane!

2. 1. What Types of Cells Have a Cell Membrane?

3. The Cell Membrane The cell membrane has many different names:
Plasma Membrane/ Fluid Membrane
Phospholipid Bilayer
Fluid Mosaic Model
The Cell Membrane
But only 1 job…

4. 2. What is the Function (job) of the Cell Membrane?
It Maintains
Homeostasis
By controlling what enters and exits the cell!

5. 3. What are the Three Main Parts of the Cell Membrane
The cell membrane is made of 3 things:
Phospholipids (phosphate & lipid)
Proteins
Cholesterol

6. 4. What does a phospholipid look like?
The head is polar and hydrophilic.
(_______________________)
Likes water like polar bears
The tail is nonpolar and hydrophobic.
Has a water phobia!

8. (mostly water)

9. 5. What is Selective Permeability?
Phospholipid bilayer is selectively permeable. This means it only allows certain things to enter and leave the cell.
What are some things the membrane lets in?
What are some things the membrane lets out?
What are some things you think the membrane might not let in?

10. Proteins come in all shapes and sizes! Shade in the Membrane Proteins!
6. What is the Structure and Function of Membrane Proteins?
Proteins come in all shapes and sizes! Shade in the Membrane Proteins!

11. 6. What is the Structure and Function of Membrane Proteins?
Transportation: Moves hydrophillic substances across the membrane.
2. Communication: Allows cells to “talk” to one another.
3. Identification: Serve as I.D. cards to let other cells know what it is.

12. 7. What is the function of cholesterol in the membrane?

13. Cholesterols Help to Maintain the Fluidity of the Membrane

14. Why do you think fluidity is important for cell membranes?
What does a fluid membrane look like?
Why do you think fluidity is important for cell membranes?