For example, when carboxyl group of
glycine combines with the amino group of alanine
we get a dipeptide, glycylalanine If a third amino acid combines to a dipeptide, the product is called a
tripeptide A tripeptide contains three amino acids linked by two peptide
linkages Similarly when four, five or six amino acids are linked, the respective
products are known as tetrapeptide, pentapeptide or hexapeptide,
respectively