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Question #46780
The Question
A patient suffering from severe systemic acidosis exhibits symptoms of polyuria and polydipsia. Laboratory analysis reveals elevated serum levels of Anti-Diuretic Hormone (ADH), yet the urine osmolarity remains abnormally low. Based on the biochemical properties of hormones and the renal system, which of the following best explains this physiological paradox?
Options
- A.
Acidosis directly inhibits the release of ADH from the neurohypophysis, leading to a condition identical to central diabetes insipidus.
- B.
The decreased systemic pH alters the ionic charges of amino acid residues on V2 receptors in the collecting duct, disrupting ADH binding affinity.
- C.
High H+ concentration in the vasa recta reverses the counter-current multiplier mechanism, preventing the establishment of a medullary osmotic gradient.
- D.
Acidosis stimulates the juxtaglomerular apparatus to release excessive renin, which competitively antagonizes the effect of ADH on the proximal convoluted tubule.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Amino Acid Zwitterion Equilibrium | ADH (Vasopressin) Logic | RAAS Pathway Feedback Loop
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating 'Biomolecules' (pH dependence of protein conformation) with 'Excretory Products and their Elimination' (Hormonal regulation of kidney function).
The common misconception is treating hormones as infallible 'magic bullets' rather than biochemical molecules subject to physiological constraints like pH and temperature.
Students often fail to recognize that receptor binding in the collecting duct can be the failure point even when hormone secretion is high.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biomolecules - Class 11 |
| Concept | Amino Acid Zwitterion Equilibrium |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |