Lipids

• Carbon, Hydrogen and Oxygen
• They are insouble in water and hydrophobic - can be dissolved in organic solvents like alcohol

Triglycerides - Compounds of fats and oils

Fatty acids combined in fats and oils have long hydrocarbon tails.The hydrophobic properties of triglycerides are due to these tails. Fatty acids are acids because their functional group (-COOH) tends to ionise slightly to produce hyrdrogen ions, which is the property of an acid.

- COOH ---------> -COO^-  + H⁺

The functional group og these three organic acids react with the three -COH functional groups of glycerol to form a triglyceride

Saturated Triglycerides

• Fats and oils that are saturated have no double bonds between the carbon atoms

Unsaturated Triglycerides

• Unsaturated fats and oils have one or more double bonds
• Fats containing several double bonds are called polyunsaturated
• Fats with unsaturated fatty acids melt at lower temperatures because their tails do not pack so closely together -(butter performs better in the fridge)

1). Energy Store

2). Protection and Insulation 

3). Waterproofing

4). Water Storage

Similar to triglycerides, excpet one fatty acid is replaced by a phosphate group

The phosphate group is ionised, having a negative charge, so water molecules are attracted to this part

Cell membranes are made almost entirely of protein and lipid, together with a small and variable amount of carbohydrate. The lipid of cell membranes is phospholipids