1. Plasma Membrane Proteins

2. 3 Types/Locations of Membrane Proteins
Integral Proteins – firmly stuck inside the membrane
Transmembrane Proteins – go from one side of the membrane to the other (a type of integral protein)
Peripheral Proteins – attached only to outer surfaces of membrane (easier to remove)

3. Integral Proteins
Peripheral Proteins
Transmembrane Protein

5. What do Proteins do for the Cell Membrane?
Help in cell-to-cell recognition
Anchor the membrane to the cytoskeleton
Help cell transport materials in/out of cell

6. Transport Proteins
Transport Proteins – move materials in and out of cell through channels that open and close
(this is how most ions pass through the membrane)
Types of Transport Proteins:
Channel Proteins = open pore for things to pass through
Carrier Proteins = selectively bind to substance and then change shape to allow passage

9. Other Parts of the Plasma Membrane
Cholesterol molecules – found inside the membrane to help keep the tails of the phospholipids from sticking together
Carbohydrates – stick out from cell and help cells identify each other using chemical signals
Cell
Cell Membrane
Carbohydrates

10. Carbohydrates on outside of cell membrane
Cholesterol stuck inside the cell membrane