A biologically important peptide for the maintenance RBC structure:

Appeared in: NVS- 2025

Explanation

Glutathione is a tripeptide composed of glutamate, cysteine, and glycine.
It is a crucial intracellular antioxidant, protecting cells from damage caused by reactive oxygen species (ROS).
In red blood cells (RBCs), glutathione specifically maintains the integrity of the cell membrane by neutralizing oxidants like hydrogen peroxide.
This protective function is essential for preventing premature destruction (hemolysis) of RBCs and maintaining their structure.

Option B: Enkephalins are neurotransmitters that modulate pain perception in the brain.
Option C: Oxytocin is a hormone that primarily stimulates uterine contractions during labor and milk ejection during breastfeeding.
Option D: Vasopressin, also known as antidiuretic hormone (ADH), regulates water balance by acting on the kidneys and also constricts blood vessels.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biochemical roles of important peptides as background academic context rather than a clinical decision trigger.
A key clinical link is Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, a genetic disorder that impairs the body's ability to regenerate the active form of glutathione in RBCs.
Nurses must be aware that patients with G6PD deficiency are at high risk for acute hemolytic anemia when exposed to oxidative stressors, including certain drugs (e.g., sulfonamides, antimalarials), infections, or foods (fava beans).
Patient education is critical, focusing on avoiding known triggers to prevent hemolytic crises.

How to Approach the Question

First, identify the keywords in the question: 'peptide' and 'maintenance of RBC structure'. This directs you to find a peptide with a structural or protective role in red blood cells.
Next, systematically review the function of each option.
Recall or deduce the primary role of Enkephalins (pain relief), Oxytocin (labor/lactation), and Vasopressin (water balance/blood pressure).
Recognize that these functions are hormonal or neurotransmitter-based and are not directly related to the physical structure of a blood cell.
Identify Glutathione as a major intracellular antioxidant. Connect its function of protecting cells from oxidative damage to the 'maintenance of structure' for RBCs, which are constantly exposed to oxygen.
Conclude that Glutathione is the only option whose function directly contributes to the structural integrity of RBCs.

Concept Tested & Keywords

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E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 51-53

E6 Biochemistry U Satyanarayana— Part 2 (pp 421-820 of 840) p. 58-60

Practise the full NVS- 2025

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