Illustrated Glossary of Organic Chemistry

Polyunsaturated fatty acid (polyunsaturated fat): A fatty acid having two or more carbon-carbon double bonds in its carbon chain.

Stearic acid lacks a carbon-carbon double bond in its carbon chain, so this molecule is a saturated fatty acid.


Oleic acid has one carbon-carbon double bond in its carbon chain, so this molecule is a monounsaturated fatty acid.


Arachidonic acid has more than one carbon-carbon double bond in its carbon chain, so this molecule is a polyunsaturated fatty acid.