Lipids or Fats: glycerol & fatty acids
Talking about lipids, we must realise that we limit ourselves here to vegetalbel oils and animal fats,
and that they all have similar kind of basic structure:
tri-esters of glycerol (1,2,3-trihidroxypropane) and fatty acids
In daily life, de difference between fat and oil is obvious (solid and liquid).
Behind this external difference is hidden a chemical difference: unsaturated and saturated fatty acids.
The unsaturated substances have a mor liquid character (oil) than the saturated ones (fat).
One molecule of glycerine connects to three molecules of fatti acid. Thus they make one molecule of lipid (fat or oil).
Besides that three molecules of water are produced.
In the example we probably see an oil.