In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C −NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid −OH) with the hydroxyl group replaced by an amine group ; or, equivalently, an acyl group −) joined to an amine group.