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Question #47675
The Question
During prolonged starvation, a mammalian cell shifts its metabolism from carbohydrates to lipids. Consider the following statements regarding this amphibolic integration and the Electron Transport System (ETS):
I. Fatty acids are degraded directly into Acetyl-CoA, completely bypassing the formation of pyruvic acid. II. The increased generation of FADH2 during lipid catabolism reduces the overall proton-pumping efficiency per electron pair compared to NADH. III. FADH2 transfers its electrons to Complex II (Succinate dehydrogenase), which then pumps protons into the intermembrane space. IV. Electrons from both Complex I and Complex II are transferred to Ubiquinone, located within the inner mitochondrial membrane.
Which of the following combinations is correct?
Options
- A.
Statements I, II, and IV are correct
- B.
Statements I, II, and III are correct
- C.
Statements II, III, and IV are correct
- D.
Only Statements I and IV are correct
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
Complex_I|Complex_II|Acetyl_CoA|Krebs_Cycle
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that FADH2 yields fewer ATPs but fail to connect this to the structural reality that Complex II is NOT a proton pump.
Furthermore, integrating the Amphibolic Pathway (fatty acids -> Acetyl CoA) with ETS energetics tests true NCERT-Plus synthesis.
The primary trap lies in Statement III, exploiting the common misconception that all numbered ETS complexes actively pump protons.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | ETS Complex Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |