query: What is a fatty acid?
passage: 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.[1] 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.
passage: Nonacosylic acid
Nonacosylic acid, or "Nonacosanoic acid", is a 29-carbon long-chain saturated fatty acid with the chemical formulaCH(CH)COOH.