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Question #45224
The Question
A novel drug acts as a competitive inhibitor of the specific carrier proteins responsible for the active reabsorption of glucose in the proximal convoluted tubule (PCT). If this drug is administered to a healthy individual with a normal fasting blood glucose level of 90 mg/dL, which of the following physiological outcomes is most likely to occur?
Options
- A.
The effective renal threshold for glucose will decrease, resulting in glucosuria and subsequent osmotic diuresis.
- B.
The Vmax of the glucose transporters will decrease, leading to obligatory water loss and severe hypoglycemia.
- C.
Glucose will escape the PCT but will be completely reabsorbed in the distal convoluted tubule (DCT) to maintain homeostasis.
- D.
The osmolarity of the filtrate entering the descending limb of the loop of Henle will decrease, producing highly concentrated urine.
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
Competitive Enzyme Inhibition Kinetics|Renal Threshold Concept|Diuretic Dynamics
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Biomolecules (Competitive Inhibition kinetics) with Human Physiology (Urine Formation).
The common misconception is that glucosuria only occurs in diabetes mellitus (hyperglycemia).
Students must deduce that competitively inhibiting PCT transporters artificially lowers the renal threshold, causing glucosuria and osmotic diuresis even at normoglycemic levels.
Furthermore, it tests the classic enzyme kinetic trap: competitive inhibitors do not alter Vmax.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biomolecules - Class 11 |
| Concept | Competitive Enzyme Inhibition Kinetics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |