The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids. About 500 amino acids are known and can be classified in many ways.
Friendly is a town in Tyler County, West Virginia, in the United States.
West Virginia, Mountain State, WV; a state in east central United States. West Virginia is a state in the Appalachian, Upland South, and Mid-Atlantic regions of the United States, bordered by Virginia on the southeast, Kentucky on the southwest, Ohio on the northwest, and Pennsylvania and Maryland on the northeast.