And we essentially continue that until we form that polypeptide that we actually want to form. So let's suppose we followed that step many, many times and eventually we formed the following polypeptide chain that consists of N number of amino acids. So this is the first amino acid that contains the group R one. And this is the last amino acid that contains the r group RN. And so this is the amino acid that we began with. And this is the final amino acid that is found on the alpha amino terminal N, while this is the one that is found on the alpha carboxyl terminal end of that polypeptide chain.