Final answer:
The enzyme enterokinase, found in the enterocyte brush border, activates pancreatic enzymes by converting trypsinogen to trypsin, which in turn activates other protein-digesting enzymes.
Step-by-step explanation:
The enterocyte enzyme that helps activate the pancreatic enzymes is enterokinase.
Enterokinase, also known as enteropeptidase, is a brush border enzyme located in the wall of the small intestine that plays a critical role in the digestion of proteins. It activates the enzyme trypsin by converting its inactive form trypsinogen, which is produced in the pancreas, into its active form. Active trypsin then initiates a cascade of enzymatic activations, converting other pancreatic proenzymes such as procarboxypeptidase and chymotrypsinogen into their active forms, carboxypeptidase, and chymotrypsin.
These enzymes are necessary for breaking down proteins into smaller peptides and amino acids, which can then be absorbed by the body. The cascade is precisely controlled to ensure protein digestion occurs only in the intestinal lumen and not inside the cells of the pancreas and intestine, preventing damage to these tissues.