The protein present in mucus is?

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-1)

Explanation

Mucin is the primary glycoprotein component of mucus, a secretion from mucous membranes.
Its main function is to provide lubrication and form a protective barrier against pathogens and foreign particles in tracts like the respiratory and gastrointestinal systems.
The high carbohydrate content of mucin allows it to trap water, giving mucus its characteristic gel-like and viscous consistency.

Option A: Gluten is a storage protein found in grains like wheat and is not produced by the human body or found in mucus.
Option C: Numiin is not a recognized biological protein. It serves as a distractor in the question.
Option D: Myosin is a motor protein essential for muscle contraction and is located within muscle cells, not mucus.

Visual 1: Diagram - A diagram showing the structure of a mucin glycoprotein, highlighting the protein core and the extensive carbohydrate side chains.
Visual 2: Illustration - An illustration of a mucous membrane (e.g., in the respiratory tract) showing goblet cells secreting mucus to trap particles.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biochemistry of Mucus Composition as background academic context rather than a clinical decision trigger.
Understanding mucus composition is crucial for managing respiratory conditions like Cystic Fibrosis, where abnormal mucin production leads to thick, sticky mucus that obstructs airways.
In Chronic Obstructive Pulmonary Disease (COPD), there is an overproduction of mucus (chronic bronchitis), which is a key diagnostic feature and therapeutic target.
What if? - If a patient has Cystic Fibrosis, the genetic defect affects the CFTR protein, leading to altered ion transport, dehydration of the airway surface, and production of abnormally thick and sticky mucus that is difficult to clear. This changes the management focus to mucolytics, airway clearance techniques, and antibiotics.

How to Approach the Question

Analyze the question to identify the core concept: It asks for the specific protein found in mucus.
Recall the basic composition of bodily secretions. Mucus is known for its slimy, protective properties.
Evaluate each option based on biological knowledge: Gluten is associated with grains/diet, not bodily secretions. Mucin's name is a strong clue, related to 'mucus'. Numiin is an unfamiliar term, likely a distractor. Myosin is associated with muscles.
Conclude that Mucin is the only plausible protein component of mucus among the choices.

Concept Tested & Keywords

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Practise the full RRB Nsg. Superintendent-20 July 2019 (Shift-1)

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