Before You Begin
Question #45213
The Question
Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone that maintains the corpus luteum during early pregnancy. Its mechanism of action involves binding to a membrane receptor and generating a second messenger. If an experimental drug specifically inhibits the phosphate esterification (phosphorylation) of intracellular target enzymes by the cAMP-dependent kinase in luteal cells, which of the following will be the most direct consequence?
Options
- A.
Adenylate cyclase will fail to convert ATP into cyclic AMP, leading to the immediate regression of the corpus luteum.
- B.
The hormone-receptor complex will fail to enter the nucleus to interact with the hormone responsive element (HRE).
- C.
The synthesis of progesterone will be arrested despite normal or elevated intracellular levels of cyclic AMP.
- D.
The primary messenger (hCG) will be degraded at the membrane, preventing the cleavage of PIP2 into IP3 and DAG.
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
Adenylate_Cyclase|hCG|Protein_Kinase_A
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the sequence of the second messenger cascade.
The trap lies in assuming that an inhibitor of the hormone's 'effect' automatically means the 'second messenger' (cAMP) is not formed.
By pinpointing the exact location of the block (at the kinase/phosphorylation level), the question tests whether the student understands that upstream events (cAMP generation) continue normally while downstream events (steroidogenesis) fail.
It also reinforces the NCERT distinction between membrane-bound (protein) and intracellular (steroid) hormone mechanisms.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biomolecules - Class 11 |
| Concept | Nucleotide Phosphate Esterification |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |