Amino acids play an essential role in the physiological processes in our body. They are the main building blocks of the principal structures in our body. Amino acids themselves or in combination with carbohydrates, lipids, etc., form an intricate system of physiologically important structures and functional domains without which life as we know it cannot exist.
From a biological point of view with respect to life forms, only 20 amino acids are important, even though many more are found in nature. Most amino acids are optically active. With the functional groups and their chemical behavior, we can predict certain properties of amino acids such as ionization properties. Amino acids join together to form peptides. Table-1 shows the pKa values of some amino acids.
Which of the following represents a peptide bond?