1. Structure and Function
Cell Membrane
Structure and Function

2. FUNCTION OF THE CELL MEMBRANE
The cell membrane controls what goes in and out of the cell.
Nutrients need to enter the cell
If they couldn’t, the cell would die from a lack of energy and building blocks.
Wastes need to exit the cell
If they couldn’t, cell would become toxic and die.

3. FLUID MOSAIC MODEL “Fluid”: able to flow and move. Like a soap bubble!
“Mosaic”: a composition of many diverse elements
Like an artistic mosaic!

4. Parts of the Cell Membrane
Carbohydrates
Phospholipid Bilayer
Membrane Proteins
Outer Surface
Cholesterol
Cytoplasm

5. Phospholipid Bilayer Structure Function
Made up of a double layer of phospholipids
Hydrophilic head & hydrophilic tails
Function
Provides overall structure for the cell membrane
Acts as a barrier between the cell and its surroundings
Holds the other components of the cell membrane

6. Proteins Structure Function Most are embedded in the cell membrane
Some are attached to the inside or outside surfaces of the phospholipid bilayer.
Function
Some transport specific substances in & out of cell
Some are enzymes, and control chemical reactions
Some receive and transmit signals to other cells in the body

7. Cholesterol Structure Function Imbedded in the phospholipid bilayer.
Helps keep the membrane fluid
Lowers fluidity of membrane in high temperatures
Increases fluidity of membrane in low temperatures

8. Carbohydrates Structure Function Cell-cell recognition
Attached to proteins or phospholipids on outside of cell.
Function
Cell-cell recognition
Allow other cells to recognize the cell as belonging to the body.
Recognize foreign invadors

9. Apply your Knowledge! Label the following diagram with the terms: Carbohydrate, Phospholipid Bilayer, Cholesterol, Protein, Phospholipid, Hydrophobic tail, Hydrophilic Head

10. Apply your Knowledge. Complete the following table
Apply your Knowledge! Complete the following table. Don’t merely copy from the notes – use your own words in point form.
Membrane Component
Structure
Function
Phospholipids
Proteins
Cholesterol
Carbohydrates