Q.2 Members of the antibody protein family that have common structural features are collectively known as
- (A) haptens
- (B) allergens
- (C) antigens
- (D) immunoglobulins
Members of the antibody protein family sharing common structural features are collectively called immunoglobulins. This multiple-choice question tests core immunology knowledge relevant to biotechnology and molecular biology exams.
Correct Answer
(D) immunoglobulins
Immunoglobulins, also known as antibodies, form a family of glycoprotein proteins produced by plasma B cells, all featuring a conserved Y-shaped structure with two heavy chains and two light chains linked by disulfide bonds. These chains include variable regions for antigen binding and constant regions determining the class (IgG, IgA, IgM, IgD, IgE), enabling shared functions like pathogen neutralization. This structural uniformity distinguishes them as a protein superfamily in immunology.
Option Explanations
Haptens (A)
Haptens are small molecules, like drugs or toxins, that cannot independently trigger immunity but become antigenic when bound to carrier proteins, lacking the proteinaceous structural features of antibodies.
Allergens (B)
Allergens are environmental substances, such as pollen or dust mites, that provoke IgE-mediated hypersensitivity reactions, acting as antigens rather than the antibodies themselves.
Antigens (C)
Antigens are foreign molecules (proteins, polysaccharides) recognized by antibodies or T-cell receptors, eliciting immune responses, but they do not describe the antibody family.
Immunoglobulins (D)
Correct choice, as this term specifically denotes the antibody superfamily with identical domain structures (VH, VL, CH, CL), crucial for adaptive immunity in biotechnology applications like diagnostics and vaccines.
