But it's this long and narrow shape and the fact that it's mostly hydrophobic, it's the shape of the S one pocket that actually gives chymetrypsin its specific nature, its specificity to Cleave only on the carboxyl end of specific side chain groups. Now, as we discussed in our study of proteases, we basically said there are many different types of proteases that exist inside our body and inside nature. Now, so far, we focused on Serene proteases and we use Chimetrypsin as the prototypical seren protease. But of course, in our body, in our digestive system, for example, we have many other examples of seren proteases. The question is, what is the mechanism that these other seren proteases actually use to cleave peptide bonds? Well, it turns out other crises also use this same catalytic triad.