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Question #47665
The Question
A metabolic poison completely inhibits the Pyruvate Dehydrogenase Complex (PDC) in a mammalian muscle cell. Which of the following statements is INCORRECT regarding the resulting metabolic crisis?
Options
- A.
The generation of GTP via substrate-level phosphorylation in the mitochondrial matrix is completely halted.
- B.
The cell becomes entirely dependent on cytoplasmic substrate-level phosphorylation for ATP production.
- C.
The continuous regeneration of NAD+ in the cytoplasm is maintained by the reduction of pyruvate to lactic acid.
- D.
The massive accumulation of Acetyl-CoA in the mitochondrial matrix triggers the allosteric inhibition of the TCA cycle.
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
Pyruvate Dehydrogenase|Acetyl-CoA|Substrate Level Phosphorylation (SLP) Sites
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Understanding metabolic blockades.
Students often memorize that 'enzyme inhibition stops the cycle' but fail to deduce the exact concentration changes.
In a metabolic pathway, the substrate of the blocked enzyme accumulates (Pyruvate), while its product depletes (Acetyl-CoA).
Option D exploits this common misconception by falsely claiming Acetyl-CoA accumulates.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | Pyruvate Decarboxylation Complexity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |