Final answer:
Trypsinogen is converted into its active form, trypsin, by the action of the intestinal brush border enzyme enteropeptidase. Active trypsin then plays a key role in digesting proteins by activating other zymogens secreted by the pancreas.
Step-by-step explanation:
Trypsin is a proteolytic enzyme initially secreted by the pancreas as an inactive precursor, trypsinogen. Activation of trypsinogen into trypsin occurs in the small intestine by the action of a brush border enzyme called enteropeptidase (also known as enterokinase). This activation is crucial for protein digestion, allowing trypsin to catalyze the hydrolysis of peptide bonds. Trypsin then activates other pancreatic zymogens such as chymotrypsinogen and procarboxypeptidase, converting them into their active forms, chymotrypsin and carboxypeptidase, respectively.
It is essential that these enzymes are secreted in inactive forms as proenzymes or zymogens to prevent them from digesting the proteins within the pancreas itself—a process which can lead to the disease pancreatitis. Once activated, trypsin and chymotrypsin work to break down large proteins into smaller peptides in a process called proteolysis, which are then catabolized into their constituent amino acids for absorption into the bloodstream.