1. Cell Membrane

2. Review Questions
What three things make up a phospholipid? Draw and label where the 3 things are located.
Draw a section of the cell membrane: where are the hydrophilic and hydrophobic regions?
What makes something hydrophilic or hydrophobic?

4. Unsaturated Fatty Acid Tails
Tails are bent (unsaturated) causing fluidity
Membranes solidify when they get cold
Membranes with unsaturated phospholipid tails solidify at a lower temperature
Organisms adapted to cold climates have more unsaturated phospholipid tails

5. Cholesterol is in between fatty acid tails to keep them from forming tight bonds

6. Semi-Permeable

7. You Shall Not Pass Can Easily pass through Cannot easily pass through
Small, uncharged, non-polar
Cannot easily pass through
Big, charged, polar (bear)
Can easily pass: water, oxygen, carbon dioxide, glycerol, amino acids (non-polar, uncharged)
Cannot pass: sodium ions, chlorine ions, glucose, amino acids (polar, charged)

8. “Fluid Mosaic Model”
Phospholipid bilayer with many “floating” parts

9. Transport Proteins Channel Proteins Gated Channels Receptor Proteins