Lipids Monomers – fatty acids & glycerol Function- repel water, insulate, store the greatest amount of energy compared to other macromolecules Found in Oils, fats, waxes, steroids, and in biological membranes

Lipid Facts! Polar molecules are neutral but because the electrons are more frequently at one side of the molecule than the other, this side behaves negative while the other behaves positive. Nonpolar molecules are neutral and the electrons spend their time equally around the molecule so all sides behave neutral Lipids are large, NONPOLAR organic molecules that DO NOT dissolve in water (water is polar)

Hydrophilic vs. Hydrophobic A molecule’s reaction with water is important to life. Molecules can be attracted to water Hydrophilic = Water loving Dissolve easily in water Molecules can be repelled by water Hydrophobic = Water fearing Do not dissolve easily in water

Saturated or Unsaturated Fatty Acids Stearic acid Solid at room temp Oleic acid Liquid at room temp Double bonds Single bonds

Phospholipids – make up the cell membrane

Cell membranes have both polar and nonpolar components