The functional group in fats is the
carboxylic acid group:
Fats or Lipids are often called fatty acids.
Generally, fatty acids have a long hydrocarbon chain with a
carboxylic acid group on the end. Saturated fats contain all single
bonds in the hydrocarbon chain. Polyunsaturated fats contain some
double bonds between carbon atoms in the hydrocarbon chain.
These fatty acids do not actually exist in that form
in fats and oils; they are present in the form of esters, the
result of a reaction between a carboxylic acid and an
alcohol,glycerol. Glyderol is a compound which has three alcohol
groups, and these combine with three fatty acid molecules to form a
triglyceride. Triglycerides serve as energy storage compounds.
Cholesterol is also a lipid found in the body.