A proteolytic enzyme secreted by chief cells in the stomach:

Appeared in: NVS- 2025

Explanation

Pepsinogen is the inactive precursor (zymogen) of the proteolytic enzyme pepsin.
It is secreted specifically by the chief cells (also known as peptic cells) located in the gastric glands of the stomach.
In the highly acidic environment created by hydrochloric acid, pepsinogen is cleaved and activated into pepsin, which then begins the process of protein digestion.
Pepsin functions optimally in a very low pH environment (1.8 to 3.5).

Option A: Gastrin is a hormone, not a digestive enzyme. It is secreted by G-cells, not chief cells.
Option B: Although gastric lipase is secreted by chief cells, it is a lipolytic enzyme (digests fats), not a proteolytic enzyme (digests proteins).
Option C: Hydrochloric acid is an acid, not an enzyme. It is secreted by parietal cells, not chief cells.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiology of Gastric Secretions as background academic context rather than a clinical decision trigger.
Understanding the roles of different gastric cells is fundamental for managing peptic ulcer disease. Excess acid and pepsin activity can erode the stomach lining.
Nurses administer medications like proton pump inhibitors (e.g., omeprazole) which block the acid-producing parietal cells, thereby reducing stomach acidity and allowing ulcers to heal.
A deficiency in intrinsic factor, secreted by parietal cells, leads to pernicious anemia. This highlights that different gastric cell dysfunctions cause distinct clinical conditions.

How to Approach the Question

First, break down the question into its core components: 1) What is being secreted? (a proteolytic enzyme), 2) Which cell is secreting it? (chief cells), and 3) Where is this happening? (in the stomach).
Define 'proteolytic enzyme' as an enzyme that digests protein.
Review each option against these criteria.
Eliminate 'Gastrin' because it's a hormone, not an enzyme.
Eliminate 'Hydrochloric acid' because it's an acid, not an enzyme, and it's secreted by parietal cells.
Compare 'Lipase' and 'Pepsinogen'. Both are secreted by chief cells, but only pepsinogen is the precursor to a proteolytic enzyme. Lipase digests fats.

Concept Tested & Keywords

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

E6 Physiology Guyton 4SAE Part 2A p. 168-170

E6 Anatomy Applied Ashalatha 4e p. 499-501

Practise the full NVS- 2025

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