Before You Begin
Question #47655
The Question
A genetic mutation renders Lactate Dehydrogenase (LDH) non-functional in a human subject. During strenuous exercise, skeletal muscle fatigue occurs rapidly due to the complete cessation of glycolysis. Which specific step of glycolysis is the immediate bottleneck directly halted by this deficiency?
Options
- A.
Conversion of Phosphoenolpyruvate (PEP) to Pyruvic acid
- B.
Conversion of Glyceraldehyde-3-phosphate (PGAL) to 1,3-bisphosphoglyceric acid (BPGA)
- C.
Conversion of Fructose-1,6-bisphosphate to Dihydroxyacetone phosphate (DHAP) and PGAL
- D.
Conversion of 3-Phosphoglyceric acid (3-PGA) to 2-Phosphoglycerate
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
NADH | Pyruvate | Lactate Dehydrogenase | Anaerobic Respiration
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that anaerobic respiration produces lactic acid but fail to grasp the 'why'—the regeneration of NAD+.
The common trap is assuming the pathway simply stops at Pyruvate (Option A) without realizing that the upstream depletion of NAD+ at the PGAL dehydrogenase step is the actual biochemical bottleneck that halts the entire glycolytic ATP yield.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | Glycolysis Redox Balance |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |