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Question #45925
The Question
In brown adipose tissue, thermogenin (UCP1) acts as an uncoupling protein in the inner mitochondrial membrane. If a chemical uncoupler with an identical mechanism of action is added to a suspension of actively respiring mitochondria, which of the following statements represents an INCORRECT physiological outcome?
Options
- A.
The proton gradient across the inner mitochondrial membrane is dissipated without passing through the F0 channel.
- B.
The terminal oxidation of cytochrome c is arrested, leading to a cessation of metabolic water formation.
- C.
The rate of electron transport through the respiratory complexes accelerates to compensate for the loss of ATP production.
- D.
The energy released from the oxidation of NADH + H+ and FADH2 is primarily dissipated as heat rather than stored.
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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
Metabolic_Water_Formation|ATP_Synthase|Thermogenin
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that if ATP synthesis (Chemiosmosis) stops, the entire Electron Transport Chain (ETC) must also stop.
This tests the ability to decouple electron flow (which produces metabolic water at Complex IV) from proton gradient utilization (which produces ATP at Complex V).
The trap relies on the misconception that metabolic water formation is directly dependent on ATP synthase activity.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | Metabolic Water Formation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |