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Question #44974
The Question
A biochemist is studying the thermal denaturation of a synthetic polypeptide at . The polypeptide exists in a functional Native state () and a Denatured state (), which are in rapid equilibrium. The denatured state further undergoes a secondary equilibrium to form a stable, inactive dimer aggregate (). The coupled equilibria are given as:
Initially, the polypeptide is prepared in a buffer such that the total monomeric concentration is (assuming initially). Once the system reaches thermodynamic equilibrium, what is the percentage of the original polypeptide that remains in the functional Native state ()?
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Numerical_Precision
Improve calculation stamina and avoid rounding errors in high-stakes competitive examinations.
Concepts Behind This Question
Protein Denaturation Specificity|Esterification Reversibility
Why This Question Is Tricky
Common Mistakes
This question tests the student's ability to handle coupled equilibria and thermodynamic sinks, drawing a parallel to Le Chatelier's Principle and solubility precipitation.
The 'Hidden Variable' trap is twofold: First, students often calculate the degree of denaturation using only , ignoring the secondary aggregation equilibrium (which acts as a thermodynamic sink, pulling the first equilibrium forward and yielding the distractor).
Second, students frequently forget the stoichiometric factor of 2 in the mass balance equation () because is a dimer, leading to an incorrect quadratic formulation.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Biomolecules - Class 12 |
| Concept | Protein Denaturation Specificity |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |