An amino acid bond between two molecules is formed when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing

The reaction is commonly seen between amino acids, and is a dehydration synthesis reaction (also known as a condensation reaction). A peptide bond at the point of CO-NH formation indicates a molecule called an amide. The four-atom functional group –C(=O)NH- is called an amide group or (in protein chemistry) A polypeptide and a protein are chains of amino acids held together by peptide bonds, as are peptide bonds in