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Question #47661
The Question
A metabolic poison specifically inhibits the enzyme responsible for the only Substrate Level Phosphorylation (SLP) step in the Tricarboxylic Acid (TCA) cycle. In a highly active skeletal muscle, this inhibition will eventually deplete the cellular ATP pool. Which of the following represents the correct identification of the inhibited step and the primary consequence of this ATP depletion on the muscle's cross-bridge cycle?
Options
- A.
Conversion of alpha-ketoglutaric acid to Succinyl-CoA; Inability of the myosin head to bind to the exposed active sites on actin.
- B.
Conversion of Succinyl-CoA to Succinic acid; Inability of the myosin cross-bridge to detach from the actin filament.
- C.
Conversion of Succinic acid to Fumaric acid; Failure of the myosin head to undergo the power stroke.
- D.
Conversion of Succinyl-CoA to Succinic acid; Inability of the myosin head to release ADP and inorganic phosphate.
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
Succinyl-CoA Synthetase|Myosin ATPase|Creatine Phosphate
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrates mitochondrial metabolism with myofibrillar mechanics.
The primary trap is the functional nuance of ATP in muscle contraction.
Students often assume ATP is directly used to 'pull' the actin (power stroke), but the power stroke is driven by the release of previously hydrolyzed ADP and Pi.
ATP binding is strictly required for cross-bridge detachment.
Additionally, it tests the precise location of SLP in the Krebs cycle, distinguishing it from oxidative decarboxylation and dehydrogenation steps.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | Substrate Level Phosphorylation (SLP) Sites |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |