The enzyme trypsin (present in the pancreatic juice) activates the inactive enzyme chymotrypsinogen into chymotrypsin.

$\underset{\left(\mathrm{Inactive}\right)}{\mathrm{Chymotrypsinogen}}\stackrel{\mathrm{Trypsin}}{\to }\underset{\left(\mathrm{Active}\right)}{\mathrm{Chymotrypsin}}$

The activated chymotrypsin plays an important role in the further breakdown of the partially-hydrolysed proteins.

$\mathrm{Proteins}\stackrel{\mathrm{Chymotrypsin}}{\to }\mathrm{Peptides}$

The other digestive enzymes of the same category are trypsinogen and
carboxypeptidase. These are secreted by the same source-gland, pancreas. Trypsinogen is present in an inactive form in the pancreatic juice. The enzyme enterokinase – secreted by the intestinal mucosa – activates trypsinogen into trypsin.

$\mathrm{Trypsinogen}\stackrel{\mathrm{Enterokinase}}{\to }\mathrm{Trypsin}+\mathrm{Inactive} \mathrm{peptide}$

The activated trypsin then further hydrolyses the remaining trypsinogen and activates other pancreatic enzymes such as chymotrypsinogen and carboxypeptidase. Trypsin also helps in breaking down proteins into peptides.

$\mathrm{Proteins}\stackrel{\mathrm{Trypsin}}{\to }\mathrm{Peptides}$

Carboxypeptidases act on the carboxyl end of the peptide chain and help in releasing the last amino acids.

$\mathrm{Peptides}\stackrel{\mathrm{Carboxypeptidase}}{\to }\mathrm{Small} \mathrm{peptide} \mathrm{chain}+\mathrm{Amino} \mathrm{acids}$