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Question #45450
The Question
During an ELISA test to detect a viral infection, a secondary antibody conjugated with an enzyme is used to generate a colorimetric signal. If a structural analogue of the chromogenic substrate is accidentally introduced into the final reaction mixture, how will it affect the diagnostic result, and which intracellular signaling event does this interference most closely mimic?
Options
- A.
It causes a false negative by preventing antigen-antibody binding, mimicking a receptor antagonist blocking a peptide hormone.
- B.
It causes a false negative by competitively inhibiting the conjugated enzyme, mimicking an intracellular inhibitor blocking adenylate cyclase despite successful hormone-receptor binding.
- C.
It causes a false positive by non-competitively inhibiting the enzyme, mimicking the failure of phosphodiesterase to degrade cAMP.
- D.
It causes a false negative by denaturing the secondary antibody, mimicking the down-regulation of membrane-bound receptors.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
ELISA|Secondary_Messenger_Cascade|Antibody-Antigen_Complex
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the stages of ELISA.
They must distinguish between the primary recognition event (Ag-Ab binding, analogous to hormone-receptor binding) and the secondary amplification event (enzyme-substrate reaction, analogous to second messenger generation).
The trap lies in assuming a substrate analogue disrupts the entire complex rather than specifically targeting the enzymatic amplification step.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Secondary Messenger Cascade |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |