Fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with a long aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually not found in organisms, but instead as three main classes of esters: triglycerides, phospholipids, and cholesterol esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and they are important structural components for cells.
Omega-3 fatty acid
Although "n" and ω (omega) are synonymous, the IUPAC recommends that "n" be used to identify the highest carbon number of a fatty acid. The more common name – omega"–"3 fatty acid – is used in both the lay media and scientific literature.