Answer :
Final answer:
Proteases in pancreatic juice are secreted as inactive enzymes to prevent self-digestion of the pancreas. They are activated in the small intestine by the enzyme enteropeptidase, ensuring safe digestion of proteins.
Explanation:
The proteases of the pancreatic juice are secreted in an inactive form to prevent the digestion of the pancreas itself, a condition known as pancreatitis. Upon reaching the small intestine, the inactive enzymes, including trypsinogen, procarboxypeptidase, and chymotrypsinogen, are activated. The enzyme enteropeptidase (formerly known as enterokinase), which is produced by the intestinal brush border, catalyzes the conversion of trypsinogen into trypsin. This active trypsin then activates other pancreatic enzymes such as procarboxypeptidase and chymotrypsinogen into their active forms, carboxypeptidase, and chymotrypsin, respectively. This mechanism ensures protein digestion occurs safely in the small intestine rather than harming the pancreas.