A 17-year-old girl presents to the emergency department with fever (39.2°C), tachypnea (RR 28), and tachycardia (HR 112). She reports ingesting a large quantity of aspirin 2 hours ago, followed by vomiting and tinnitus. Arterial blood gas reveals pH 7.28 with elevated lactate (5.2 mmol/L). Despite markedly increased oxygen consumption, her cells generate less ATP while producing excessive heat. She denies recent illness. Which mechanism best explains her altered cellular energy metabolism?
- A)Uncoupling of oxidative phosphorylation by dissipating the proton gradientGABARITO
- B)Inhibition of ATP synthase
- C)Inhibition of cytochrome c oxidase
- D)Activation of glycogen phosphorylase only
- E)Blockade of ADP entry into mitochondria
Explicação
High dose salicylates can uncouple oxidative phosphorylation by making the inner mitochondrial membrane permeable to protons. Electron transport and oxygen consumption continue, but ATP synthesis falls because the proton gradient is dissipated and energy is re... Ver explicação completa e trilha adaptativa →