1. Lipids Made up of C, H and O Can exist as fats, oils and waxes
They are insoluble in water
They are a good source of energy
They are poor conductors of heat
Most fats & oils are triglycerides

2. Triglycerides
…a condensation reaction between 3 fatty acids and glycerol: H H C O
Glycerol H

3. Fatty acids Carboxyl group (-COOH)
attached to a long non-polar hydrocarbon chain (hydrophobic): C O H H C H C H C H
A saturated fatty acid (no double bonds)

4. A monounsaturated fatty acidH C H H C H C O C H C H C H C C O H H
A monounsaturated fatty acid H C H H H C O C C H C H C C C O H H H
A polyunsaturated fatty acid

5. Formation of an ester bondH H C O C O H H
Fatty acid
Glycerol

6. H H C O C O H H
Fatty acid
Glycerol

7. Condensation Fatty acid Glycerol H C O H H C O H C H H C H O H C H C C

8. Esterification Ester bond water C O H H C O H C H H C H O H C H C C C

9. Esterification This happens three times to form a triglyceride:
glycerol
fatty acids

10. Functions of lipids Protection of vital organs
To prevent evaporation in plants & animals
To insulate the body
They form the myelin sheath around some neurones
As a water source (respiration of lipids)
As a component of cell membranes