Terpenoids-lipids including carotenoids and steroids
Acylglycerols
One of the most important groups of lipids
Chemical Composition of Acylglycerols
Composed of glycerol and fatty acids. Chemically, acylglycerols can be defined as esters of fatty acids and alcohol
Ester formation
Alcohol + Acid -> Ester + Water
Triacylglycerol
The most widely spread acylglycerol, also called triglycerides or neutral lipids
Triacylglycerol is composed of one glycerol and three fatty acids molecules
Fatty acids
Contain even numbers (2-30) of carbon atoms in straight chain attached with having an acidic groups COOH (carboxylic group)
May be saturated (no double bonds) or unsaturated (up to 6 double bonds)
In animals, they are straight chains, in plants they may be branched or ringed
Solubility and melting points increase with increasing number of carbon atoms
Fats
Containing saturated fatty acids, solid at room temperature
Oils
Containing unsaturated fatty acids, liquid at room temperature
Fats and oils are lighter than water and have a specific gravity of about 0.8. They are not crystalline but some can be crystallized under specific conditions
