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Question #45142
The Question
Transgenic animals are preferred over bacterial bioreactors for the commercial production of complex human therapeutic proteins like alpha-1-antitrypsin (used to treat emphysema). If a researcher successfully clones the human alpha-1-antitrypsin cDNA into an E. coli expression vector under a strong prokaryotic promoter, the extracted protein is still found to be biologically inactive. Which of the following best explains this failure?
Options
- A.
Prokaryotic ribosomes translate eukaryotic mRNA with lower fidelity, causing frequent missense mutations that alter the active site.
- B.
E. coli lacks the eukaryotic endomembrane system and specific chaperones required for essential post-translational modifications like glycosylation.
- C.
The prokaryotic promoter generates transcriptional 'noise', resulting in a polycistronic mRNA that bacterial ribosomes cannot translate.
- D.
Bacterial restriction endonucleases immediately degrade the human cDNA because it lacks prokaryotic methylation patterns.
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
ADA_Deficiency|Alpha-1_Antitrypsin|Transgenic_Animal_Purpose
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that satisfying the Central Dogma (DNA -> RNA -> Protein) guarantees a functional product.
This question tests the integration of Cell Biology (endomembrane system functions) with Biotechnology, highlighting the common misconception that bacterial vectors can produce any human protein, ignoring the critical necessity of post-translational modifications for complex proteins like alpha-1-antitrypsin.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology and Its Applications - Class 12 |
| Concept | ADA Deficiency Genetic Correction |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |