So let's begin with trypsin. So Trypsin catalyzes the cleavage of peptide bonds on the carboxyl end of Lysine and Arginine. And if you recall, Lysine and Arginine both contain positive charges on their sidechain groups. Now, the question is, why is this true? So Trypsin uses the same exact catalytic triad that climate Trypsin uses. But what gives this Trypsin the difference in specificity?