Fatty acid

A fatty acid is any compound with a COOH group (which are called carboxylic acids) and a long unbranched tail made only from hydrogen and carbon. Fatty acids can bond with glycerin to form lipids like fat, oil, wax, and grease. Fatty acids can be metabolized as a source of energy for calories.

The hydrocarbon tails can be comprised of single bonded carbon atoms that are attached to the hydrogen atoms. When the carbon is single bonded it can hold the most hydrogen, or is saturated with hydrogen. When the fatty acids bond with glycerin they are refereed to as saturated fat. The hydrocarbon tail can also be comprised of one or more double bonded carbon atoms, which prevent the chain from holding as many hydrogen atoms. When bonded with glycerin they are refereed to as unsaturated fat, of which monounsaturated fat contains only one double carbon bond, with polyunsaturated fat containing two or more double carbon bonds.

Fatty acids can be referred to by their length, with short chain fatty acids (SCFA) having five or fewer carbons, medium-chain fatty acids (MCFA) such as MCTs having 6-12 carbons, long-chain fatty acids (LCFA) having 13-21 carbons, and very long chain fatty acids (VLCFA) having 22 or more carbons.