Now, amino acid A contains a side chain group given by R one, and this one contains a different side chain group given by R two. And any one of these amino acids can be any one of the 20 amino acids found inside our body. For example, this can be Glycine and this can be Lysine and so forth. Now, under certain conditions, these two reactants will react, and they will produce the following product. Now, product C is a dipeptide, and a dipeptide simply means we have two amino acids connected by a peptide bond that is shown in green. So this carbon on product C is this carbon on reactant A, and this nitrogen on product C is this nitrogen on reactant B.