Which inactive digestive enzyme is present in Pancreatic juice?

Appeared in: AIIMS Raipur NO- 2019 (shift 3rd)

Explanation

Trypsinogen is the inactive precursor (zymogen) of the digestive enzyme trypsin.
It is produced and secreted by the acinar cells of the pancreas into the pancreatic juice.
Storing the enzyme in an inactive form is a critical protective mechanism that prevents the pancreas from digesting its own tissues.
Activation occurs safely away from the pancreas, in the duodenum, upon contact with the enzyme enteropeptidase.

Option B: Renin is not a pancreatic enzyme. It is primarily secreted by the kidneys to regulate blood pressure.
Option C: Ptyalin, or salivary amylase, is found in saliva, not pancreatic juice. Its function is to start carbohydrate digestion in the mouth.
Option D: Erepsin is a term for a group of peptidases found in the intestinal juice (succus entericus), not pancreatic juice. It is involved in the final breakdown of proteins.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biochemistry of Digestion: Pancreatic Enzymes as background academic context rather than a clinical decision trigger.
Understanding zymogens is crucial for comprehending diseases like acute pancreatitis. In this condition, pancreatic ducts can become blocked, leading to the premature activation of trypsinogen to trypsin within the pancreas itself.
This internal activation causes the pancreas to start digesting its own tissue (autodigestion), leading to severe inflammation, pain, and tissue damage. This is a medical emergency.
Nursing care for pancreatitis involves resting the pancreas (NPO - nothing by mouth), managing pain, and monitoring for complications of autodigestion like hemorrhage and shock.

How to Approach the Question

First, identify the key terms in the question: "inactive digestive enzyme" and "Pancreatic juice". This tells you to look for a zymogen (inactive enzyme) specifically from the pancreas.
Second, review each option and recall its origin and function.
Third, evaluate Option A, Trypsinogen. Recall that "-ogen" is a common suffix for inactive enzyme precursors, and trypsin is a well-known pancreatic enzyme.
Fourth, eliminate the other options by identifying their source: Renin (kidney/stomach), Ptyalin (saliva), and Erepsin (intestine).
Finally, confirm that Trypsinogen is the only option that is both an inactive enzyme and originates from the pancreas.

Concept Tested & Keywords

QJGUQI80UjbIsItATvRhKx

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 74-76

E6 Physiology Guyton 4SAE Part 2A p. 174-176

Practise the full AIIMS Raipur NO- 2019 (shift 3rd)

Attempt every question from this paper in a timed mock, then review the full solution for each one.