Proteins consist of amino acids linked together by peptide bonds (-CONH-). A peptide bond is formed by the elimination of water molecule during reaction between carboxyl (-COOH) group of one α-amino acid and amino (-NH2) group of another α-amino acid.
R R R R
l l – H2O l l
H2N-CH-COOH + HNH-CH-COOH ------------------------→ H2N-CH-CONH-CH-COOH
α-amino acid α-amino acid Formation of Peptide Bond
