1. Lipids and Cell Membrane Structure

2. Lipids make up MOST of the cell membrane
Lipids are not soluble in water
Lipids store large amounts of energy
The monomers (smallest part of a lipid) are called fatty acids
Fatty acids can combine to make complex lipids by a reaction called dehydration synthesis (aka condensation)

3. Fatty Acids – unbranched carbon chain that makes up most lipids
2 parts:
1. Carboxyl Head
-COOH
Polar – attracted to water
Hydrophilic – “water loving”
2. Hydrocarbon Tail
H-C chain
Nonpolar – stays away from water
Hydrophobic – “water fearing”

4. Types of Fatty Acids Saturated Unsaturated
Each C always bonded to 4 other atoms
Molecule contains the max. # of H atoms
Unsaturated
Double/triple bonds between some C atoms
Less H atoms needed
Stop here to complete the lipids portion of the molecular models activity.

5. Phospholipids are lipids with 2 fatty acids attached to one glycerol
Phospholipids are lipids with 2 fatty acids attached to one glycerol. They have a polar and a non-polar end that align in the cell membrane forming a bi-layer

6. Cell Membrane Structure
The cell membrane contains fats, proteins, and carbohydrates.

7. 2 Kinds of cell membrane proteins
Integral Proteins
Proteins that penetrate completely through the lipid bilayer (inside)
Function to help transport different substances into and out of the cell.
2. Peripheral Proteins
Embedded into the bilayer
Located on the outside surface
fluid mosaic model

8. Cell Membrane Functions
It controls what enters and exits the cell. It is considered selectively permeable since it only lets certain molecules into and out of the cell
It maintains the cell shape
It connects each cell to other cells near it
It can allow movement of the cell because the parts can move around each other, called the fluid mosaic model
fluid mosaic model