Metabolism USMLE Step 1 Practice Question
A 61-year-old groundskeeper with decades of pesticide exposure presents with progressive resting tremor, bradykinesia, and rigidity. Vital signs: BP 138/82, HR 62, RR 16, Temp 37°C, SpO2 98%. MRI shows preserved striatal volume without iron deposition. Serum copper and ceruloplasmin are normal. Research testing reveals selective inhibition of electron transfer from NADH to coenzyme Q in his dopaminergic neurons. Which mitochondrial component is most likely inhibited?
Answer choices
- AComplex III
- BComplex ICorrect answer
- CComplex IV
- DATP synthase
- EComplex II
- FF. Pyruvate dehydrogenase complex
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