1. The Cell Membrane

2. Cell Membrane Basics
Function: Controls the passage of materials into and out of a cell
Semi-Permeable: only some materials may enter/exit
Double layer of phospholipids (bilayer)

3. Phospholipid Composition
3 Parts
Polar Head
1) Phosphate Group
2) Glycerol
Nonpolar Tails
3) Two chains of fatty acids
Arrangement:
Outside: Polar heads (hydrophilic)
Inside: Nonpolar Tails (hydrophobic)

4. Phospholipid Bilayer

5. Cell Membrane Contents
1) Cholesterol Molecules: strength
2) Carbohydrates: identification
3) Various Proteins

7. Membrane Proteins Randomly scattered through bilayer Various Functions
Cytoskeleton: internal support
Protein channels: allow objects to pass
Enzymes: speed up chemical reactions
Markers (carb. chains): cell recognition; fight disease

8. Receptor Proteins Help cells communicate Binds to ligands Two kinds
EX: hormones, neurotransmitters
Two kinds
Membrane
Intracellular

9. Draw, identify, label, & describe
carbohydrate
chain
protein
cholesterol
protein
protein channel
cytoskeleton

10. Review Name the 3 parts to a phospholipid?
Which part(s) make up the head of a phospholipid?
Which part(s) make up the tails of a phospholipid?
Which part of phospholipid always seems to be in contact with a watery environment? Why?
Draw and label the basic components of the cell membrane.
Which membrane protein supports the cell membrane?
Which membrane protein allows materials to pass through?