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.
Swansboro, North Carolina, known as the Friendly City by the Sea, is a quaint, historic town located on the North Carolina Coast boarding both the IntraCoastal Waterway and the White Oak River.