General ---------Biology----------------------------------------------------- ------------------Online--------------------------------------- Ch. 5 Macromolecules: carbohydrates, lipids, proteins, nucleic acids

The synthesis of a fat requires an enzyme to catalyze a condensation reaction between three fatty acids and a glycerol molecule. 

The fat shown above is called a saturated fat because the fatty acid regions are "saturated" with hydrogen's.  You can recognize a saturated fat molecule by its shape, i.e. the hydrocarbon chains are straight.  But if a hydrogen is removed from a carbon, the carbon will double bond with its adjacent carbon forming an angle or a kink in the molecule.  Once a hydrogen is removed from a hydrocarbon chain, it is called "unsaturated."

DHA image 1
DHA image 2