This set of Structural Biology Multiple Choice Questions & Answers (MCQs) focuses on “Immunoglobulin – Set 2”.
1. How many antibodies are bound to a human B cell?
a) 20,000-50,000
b) 50,000-100,000
c) 10,000-30,000
d) >100,000
View Answer
Explanation: When antigens bind to antibodies, they cluster together and form large patches, which increase the efficiency of cellular immune response.
2. The property that explains antigen-antibody interactions is _______
a) Specificity
b) Affinity
c) Lock and key pattern
d) Allosteric effect
View Answer
Explanation: The lock and key pattern, also called spatial complementarity, is the binding site on the antibody present in the antigen-binding fragment (Fab). Since the interactions are weak and noncovalent, antigen-antibody binding is reversible, which at times leads to cross reaction of antibodies with different antigens.
3. Which of these are the types of heavy chains present in immunoglobulins?
a) Alpha, beta, gamma
b) Epsilon, gamma, delta
c) Si, phi, mu
d) Alpha, delta, epsilon, gamma, mu
View Answer
Explanation: Alpha, delta, epsilon, gamma, mu are the heavy chains present individually in IgA, IgD, IgE, IgG, IgM respectively. It is these that classify the immunoglobulins and segregate them based on their functions.
4. Which of the following is not a function of an immunoglobulin?
a) Precipitation
b) Neutralisation
c) Combination
d) Agglutination
View Answer
Explanation: Precipitation is where antibodies gather together the serum-soluble antigens, form a precipitate and is ready for phagocytosis. Neutralisation is the phenomenon when antibodies block certain parts of the attacking bodies which reduces their impact. Agglutination is the gluing together of antigens into clusters which are then exposed to phagocytosis.
5. Antibodies and immunoglobulins are the same.
a) False
b) True
View Answer
Explanation: While both are glycoproteins, immunoglobulins are immobile, attached to the surface of B cells and have a transmembrane domain, whereas antibodies are found afloat in body fluids, without any transmembrane domains.
6. The variable region can be further divided into _____
a) Hypervariable and framework regions
b) Hypo variable and framework regions
c) Hypervariable and boundary regions
d) Hypo variable and boundary regions
View Answer
Explanation: Hypervariable region is one where the ratio of uncommon amino acids to the relatively common amino acids in a specific location is high. The framework region forms beta sheets that supports the hypervariable region stable for the antigen contact.
7. Which part of an antibody is the Fab region?
a) Antigen-antibody interaction site
b) Variable regions
c) Constant regions
d) Regions where disulphide bonds are formed
View Answer
Explanation: There are two identical antigen-antibody binding sites present, which specifically bind to the antigens in a lock and key fashion. This is where an antigen-antibody complex is formed.
Sanfoundry Global Education & Learning Series – Structural Biology.
To practice all areas of Structural Biology, here is complete set of Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
