Fatty
acids are the building
units of fats consisting of longer chains than
acidic acid (ethanoic acid).
Butaric acid
(left down) has 4 C atoms,
Dodecanoic
acid (right down) has 12 C atoms,
Palmitoleic
acid (up) an unsaturated acid has 16 C atoms.
For
unsaturated acids see cis- and trans fatty acids.
A
fat molecule
is formed by 3 of those molecules of fatty acid fusing with 1 molecule
of gycerol (photo middle).