Triglycerides are composed of 1 glycerol and 3 fatty acids
Saturated fatty acids have no double bonds, but unsaturated fatty acids have kinks in their chains.
Fats are saturated and act as short term energy stores, but oils are unsaturated and act as long term energy stores.
Phospholipids are the main components of the cell membrane and consist of one glycerol, two fatty acids and one phosphate group.
Steroids include cholesterol which is an essential component of the cell membrane and the sex hormones.
Steroids differ from other lipids because their skeletons have four fused carbon rings. However, they are classified as lipids because of their hydrophobic nature.