1. LIPIDS fats, oils, phospholipids, waxes & steroids

2. Lipids
Lipids are organic molecules that are non-polar therefore are insoluble in water (Hydrophobic)

3. Functions of Lipids
Long-term energy storage in cells (Lipids contain 9.1 calories of energy per gram compare to carbohydrates and proteins with about 4.4 calories per gram)
Structural component of cell membranes (Phospho lipid bilayer)
Insulation (blubber)
Padding (protection for our vital organs i.e heart)
Chemical messengers (hormones)

4. 4 main types of lipids Fatty acids Neutral fats or triglycerides
Phospholipids
steroids

5. 1. Fatty acids
Long chains of hydrocarbons ending in - COOH (Carboxyl group)
Fatty acids may be saturated fatty acids or unsaturated fatty acids or trans-fatty acids

6. Saturated fatty acids are SOLID at room temperature (Lard)
They do not contain any double bonds in the hydrocarbon chain
Unsaturated fatty acids are LIQUID at room temperature (oils)
They contain 1 or more double bonds causing the hydrocarbon chain to bend

7. Fatty acids
Cis and Trans-fatty acids refers to the configuration of the hydrogen atoms
Industrial (artificial) Trans fats are produced by hydrogenation or chemically adding hydrogen to convert vegetable fats into solid form in processed foods (to increase shelf life). These increase LDL (“bad” cholesterol) in our blood.

8. 2. Neutral fats (Triglycerides)
Storage form of fat (energy) in animals
Composed of GLYCEROL and 3 FATTY ACIDS combined together by dehydration synthesis
The fatty acids may be saturated or unsaturated

9. Some lipids are phospholipids that form cell membranes.
Phospholipids are composed of GLYCEROL, 2 FATTY ACIDS and a PHOSPHATE group
Phospholipids have a POLAR head and a NON-POLAR tail

10. Steroids are lipids derived from cholesterol.
Steroids are made of carbon rings instead of chains
Steroids function as chemical messengers and important hormones such as estrogen and testosterone.

11. Makes vitamin D and bile
Cholesterol
Cholesterol is also found as part of the structural component of cell membranes
Makes vitamin D and bile

12. Emulsifiers cause fats to mix with water.
Emulsification
Emulsifiers cause fats to mix with water.
The molecules of emulsifiers have a polar end and a non-polar end.
These molecules position themselves around oils so that their non-polar end project inwards and their polar ends project outwards allowing the oils to become attracted to water