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Proteolytic enzymes secreted from the pancreas are activated: a) within the lumen of the small intestine. b) once they reach the large intestine. c) in secretory vesicles within pancreatic secretory cells. d) once they reach the pancreatic duct.

2 Answers

6 votes

Final answer:

Proteolytic enzymes from the pancreas like trypsinogen and chymotrypsinogen are activated within the lumen of the small intestine by enteropeptidase. They are secreted in an inactive form to protect the pancreas and are only activated when they reach the small intestine's duodenum.

Step-by-step explanation:

Proteolytic enzymes secreted from the pancreas are activated within the lumen of the small intestine. Pancreatic juice carries inactive enzymes, such as trypsinogen and chymotrypsinogen, via the pancreatic duct. These are subsequently activated by enteropeptidase, an enzyme secreted by the intestinal mucosal cells, which converts trypsinogen to trypsin. Trypsin then further activates other proteolytic enzymes such as chymotrypsinogen to chymotrypsin, and procarboxypeptidase to carboxypeptidase.

The pancreas produces these enzymes as inactive proenzymes to prevent the digestion of its own tissues. Activation occurs in the duodenum, where the brush border enzyme enteropeptidase stimulates proteolytic activity. This system ensures that protein digestion is completed effectively without harming the pancreas or the small intestine.

User Yamel
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3 votes

Answer:

A) within the lumen of the small intestine.

Step-by-step explanation:

The pancreas produces a variety of hormone-like amylase, proteases, lipases which can digest the food material.

The proteases like chymotrypsinogen and trypsinogen are produced by the pancreas in their inactive form as if active will digest the organ itself. Therefore these zymogens are stored in the secretory vesicles which release the enzymes in the pancreatic duct.

These zymogens are not activated until they reach the digestive tract that is when these enzymes enter the lumen of the small intestine, the enterokinase present there catalyzes the trypsinogen to trypsin. Trypsin converts the chymotrypsinogen to the chymotrypsin.

Thus, Option-A is the correct answer.

User Sudhir Chauhan
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4.9k points