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Question #46707
The Question
During aestivation (summer sleep), a frog relies solely on cutaneous respiration and its metabolic rate drops significantly. Based on the principles of cellular metabolism and enzyme kinetics, which of the following best explains how this state of minimal respiration indirectly halts gastric protein digestion at the cellular level?
Options
- A.
Decreased terminal electron acceptance in the ETS reduces metabolic water formation, increasing cytosolic ionic strength and destabilizing the enzyme-substrate complexes of proteases.
- B.
The cessation of pulmonary respiration causes severe intracellular acidosis, which competitively inhibits the HCl-mediated activation of pepsinogen.
- C.
Reduced oxygen intake directly denatures the tertiary structure of gastric enzymes, permanently altering their active sites.
- D.
The lack of metabolic energy halts bile production, preventing the emulsification of dietary proteins required for protease action.
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
Frog Digestive Enzyme Specificity|Metabolic Water Formation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating 'Metabolic Water' (from Respiration/ETS) with 'Enzyme Kinetics' (Biomolecules) in the context of 'Frog Physiology' (Structural Organization).
Students often memorize that digestion stops during dormancy but fail to connect the respiratory drop (and subsequent lack of metabolic water) to the osmotic/hydration changes that alter enzyme-substrate affinity.
Option D exploits a common functional confusion by substituting 'proteins' for 'fats' in the context of bile emulsification.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Structural Organisation in Animals - Class 11 |
| Concept | Frog Digestive Enzyme Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |