Question u Why do fats usually contain saturated fatty acids and oils usually contain unsaturated fatty acids? u The double bond pushes the molecules apart, lowering the density, which lowers the melting point.
Fats u Differ in which fatty acids are used. u Used for energy storage, cushions for organs, insulation.
Question ? u Which has more energy, a kg of fat or a kg of starch? u Fat - there are more C-H bonds which provide more energy per mass.
Phospholipids u Similar to fats, but have only two fatty acids. u The third -OH of glycerol is joined to a phosphate containing molecule.