Enzyme Technology Multiple Choice Questions on “Biosensors – Immunosensors”.
1. Abbreviation of ELISA is __________________
A. Ion Selective Field Effect Transistors
B. Enzyme Linked Field Effect Transistors
C. Adenosine triphophosphate
D. Enzyme Linked Immunosorbent Assay
Answer: D
Clarification: Abbreviation of ELISA is Enzyme Linked Immunosorbent Assay. Ion Selective Field Effect Transistors is the full form of ISFET, whereas Enzyme Linked Field Effect Transistors is the full form of ENFET. ATP is abbreviated as adenosine triphosphate.
2. ______________ is used to detect and amplify an antigen-antibody reaction.
A. Calorimetric biosensor
B. Optical biosensor
C. ELISA
D. Potentiometric biosensor
Answer: C
Clarification: ELISA is used to detect and amplify an antigen-antibody reaction. Calorimetric biosensor involves measuring the heat generated during a reaction. Potentiometric biosensors make use of ion-selective electrodes in order to transduce the biological reaction into an electrical signal. Optical biosensor determines changes in light or measuring the light output.
3. ELISA techniques have been combined with biosensors to form __________
A. calorimetric biosensor
B. piezo-electric biosensor
C. immunosensor
D. potentiometric biosensor
Answer: C
Clarification: Immunosensor has been formed by combining ELISA techniques with the biosensor. The heat generated during a reaction is measured by using calorimetric biosensor. Piezo-electric biosensor measures the effects formed due to the mass of the reactants or products. Potentiometric biosensor measures the changes in the distribution of charges causing an electrical potential to be produced.
4. _________ is a substance that stimulates the immune system to produce antibodies.
A. Antigen
B. Antibody
C. Antigen enzyme conjugate
D. Antibody enzyme conjugate
Answer: A
Clarification: Antigen is a substance that stimulates the immune system to produce antibodies. Antigens can be bacteria, viruses, or fungi that cause infection and disease. Antibodies are substances that help fight against foreign substances. Antigen and antibody covalently linked to enzyme is referred to as antigen enzyme conjugate and antibody enzyme conjugate respectively.
5. Y-shaped protein molecules manufactured by the body that help fight antigens is referred to as _____________
A. antigen
B. antigen enzyme conjugate
C. antibody enzyme conjugate
D. antibody
Answer: D
Clarification: Antibodies are Y-shaped protein molecules manufactured by the body that help fight against foreign substances called antigens. These are also called immunoglobulins. Antigen is a substance that stimulates the immune system to produce antibodies. Antigen covalently linked to the enzyme is referred to as antigen enzyme conjugate, whereas and antibody covalently linked to enzyme is referred to as antibody enzyme conjugate.
6. What is represented in the following diagram?
A. Piezo-electric biosensor
B. Calorimetric biosensor
C. ELISA
D. Immunosensor
Answer: C
Clarification: The diagram represents the principle of ELISA. Steps involved in ELISA are:
• Antibody is immobilised on the surface of a tube and a mixture of a known amount of antigen-enzyme conjugate plus unknown concentration of sample antigen is placed in the tube and allowed to equilibrate.
• After a suitable period, the antigen and antigen-enzyme conjugate will be distributed between the bound and free states dependent upon their relative concentrations.
• Unbound material is washed off and discarded. The amount of antigen-enzyme conjugate that is bound may be determined by the rate of the subsequent enzymic reaction.
7. What is represented in the following diagram?
A. Optical biosensor
B. Amperometric biosensor
C. ELISA
D. Immunosensor
Answer: D
Clarification: Principle of Immunosensor is represented in the diagram. ELISA is performed initially and then the following steps are followed:
• A transducer is coated with immobilized antibody. The transducer is immersed in a solution containing a mixture of a known amount of antigen-enzyme conjugate plus the unknown concentration of sample antigen.
• After a suitable period, the antigen and antigen-enzyme conjugate will be distributed between the bound and free states dependent upon their relative concentrations.
• Unbound material is washed off and discarded. The amount of antigen-enzyme conjugate bound is determined directly from the transduced signal.
