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Question #45779
The Question
Statins, widely used to inhibit HMG-CoA reductase, can cause myopathy as a side effect by depleting Coenzyme Q10, thereby severely reducing mitochondrial ATP synthesis in skeletal muscle fibers. If intracellular ATP levels drop drastically in these fibers, at which specific step of the actin-myosin interaction will the cross-bridge cycle primarily arrest?
Options
- A.
During the power stroke, as ATP hydrolysis directly pulls the actin filament towards the center of the A-band.
- B.
Immediately after the power stroke, as the binding of a new ATP molecule to the myosin head is required for cross-bridge detachment.
- C.
Prior to cross-bridge formation, as ATP binding is required to unmask the myosin-binding sites on F-actin.
- D.
During the recovery stroke, as ATP is directly required to release calcium ions from the Troponin-C subunit.
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
Sarcomere Functional Boundaries|Statin Mechanism of Action|Coenzyme Q10 Depletion
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often harbor the misconception that ATP is solely required to 'power' the contraction (the power stroke).
However, NCERT explicitly details that the binding of intact ATP is the absolute prerequisite for the detachment of the myosin head from actin.
Failing to recognize ATP's role in muscle relaxation leads to selecting incorrect options regarding the power stroke.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Sarcomere Functional Boundaries |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |