1. Cell Membrane
SC.912.L.14.2 Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective barrier (passive and active transport)

2. Cell Membrane
Objective: Describe the structure of the cell membrane and explain how it contributes to its function
EQ: How is the structure of the cell membrane related to its function?
How is the structure of the cell membrane related to its function?

3. Turn and Talk
You’re one of the main characters in The Walking Dead zombie apocalypse. You’re trying to find somewhere protected to stay long-term. What are some things you’d need to consider about the type of shelter you need?

4. Cell Membrane Structre
Cell membranes are made of phospholipids, a type of lipid that has a polar phosphate head and two fatty acid tails
Which part of this molecule would be attracted to water? Why?

5. Cell Membrane: Structure
Phosphate Head
Fatty Acid Tails
The polar phosphate head is hydrophilic (water loving)
the tails are nonpolar and hydrophobic (water hating).
What does it mean to be polar?

6. Check for Understanding
Why is the arrangement of phospholipids in the membrane called a bilayer?
The prefix bi means two; since there are two layers of phospholipids, it is called a bilayer
Which part of the phospholipid would be on the outside?

7. Cell Membrane Structure
The phospholipids form a bilayer with the hydrophobic tails inside, protected from the water

8. Stop and think
Think about the structure of the CM, what material do you think will pass through easily?
Why?

9. Selective Permeability
Cell membranes are selectively permeable, some materials can pass through the membrane while others cannot

10. Parts of the Membrane
the cell membrane also contains proteins, carbohydrates, and cholesterol
All of the molecules are in constant motion, sliding past one another. This is called the fluid mosaic model.
cell membrane
protein
cholesterol
carbohydrate
chain
protein channel
Fluid because they ripple and move if your poke the cell.

11. Parts of the Membrane: Channel Protein
provide places for molecules to move across the membrane (either into or out of the cell)
Ex: Like tunnels/ channels

12. Parts of Cell Membrane: Cholesterol
helps provide strength to the cell membrane
Ex: structural support

13. Parts of Cell Membrane: Carbohydrates
help identify and distinguish the cell from other types of cells
Ex: state flags in the U.S.

14. MAIN Part of Cell Membrane: Phospholipid
creates barrier around cell with the hydrophobic tails facing in and the hydrophilic heads facing out
Ex: security

15. Cell Membrane: Function
There are two main functions of the cell membrane:
Protects from outside environment - forms boundary between the inside and outside of the cell
Controls what enters and exits the cell – because it is semi-permeable

16. Think, Pair, Share
Why might it be important for a cell to regulate the materials moving into and out of it?
Conditions outside the cell are constantly changing. However, a cell must maintain homeostasis to carry out its functions. To do this, it must be able to control the movement of particular molecules across the cell membrane.

17. H- work with your partner
Build a Membrane
C – level 2 voice
H- work with your partner
A- build a model membrane out of the materials provided
M- remain seated in your assigned seat
P- complete your activity sheet with justrifications
Success!
Working with a partner, build a membrane out of the materials provided.

18. Exit Ticket
Clear you desk of everything except something to write with!