Which proteins are classified based on their functions?

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Explanation

Proteins can be classified based on their biological function, which describes their role in physiological processes.
Protective proteins are a functional class of proteins.
Their primary role is to defend the body against foreign invaders and injury.
Examples include immunoglobulins (antibodies) which fight infection, and fibrinogen and thrombin which are essential for blood clotting.

Option A: Globular proteins are classified based on their molecular shape, not their function. They are typically spherical or globe-like.
Option B: Fibrous proteins are also classified based on their molecular shape. They are long, fiber-like, and typically provide structural support.
Option D: Simple proteins are classified based on their chemical composition. They consist only of amino acid residues.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of proteins as background academic context rather than a clinical decision trigger.
Understanding protein classification is crucial in clinical practice. For example, measuring levels of specific transport proteins like albumin can indicate liver or kidney disease.
Knowledge of protective proteins is fundamental to immunology and hematology. Low levels of immunoglobulins can indicate an immunodeficiency, while issues with clotting factors lead to bleeding disorders.
What if a patient has severe edema (swelling)? A nurse might suspect low levels of the transport protein albumin, which maintains oncotic pressure in the blood. This would prompt a check of liver function tests.

How to Approach the Question

First, identify the key terms in the question: 'proteins', 'classified', and 'functions'. The question asks to identify the protein group that is defined by its role in the body.
Next, analyze each option to determine its basis for classification.
Recall or deduce that 'Globular' and 'Fibrous' describe physical shapes.
Recall or deduce that 'Simple' describes chemical composition (containing only amino acids).
Recognize that 'Protective' describes a biological role or action (e.g., defense).
Conclude that 'Protective proteins' is the category classified by function.

Concept Tested & Keywords

Q48cM2wcC3rE_AFPVfBF2v

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 108-110

E6 Nutrition Monika Sharma 3e p. 82-84

E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 96-98

Practise the full RRB Nsg. Superintendent-20 July 2019 (Shift-2)

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