A 33-year-old woman is brought to the emergency department 30 minutes after being rescued from a fire in her apartment. She reports nausea, headache, and dizziness. Physical examination shows black discoloration of her oral mucosa. Pulse oximetry shows an oxygen saturation of 99% on room air. The substance most likely causing symptoms in this patient primarily produces toxicity by which of the following mechanisms?
AInhibition of mitochondrial complex V
BDegradation of 2,3-bisphosphoglycerate
COxidation of Fe2+
DRise in serum pH
ECompetitive binding to heme
A 24-year-old professional athlete is advised to train in the mountains to enhance his performance. After 5 months of training at an altitude of 1.5 km (5,000 feet), he is able to increase his running pace while competing at sea-level venues. Which of the following changes would produce the same effect on the oxygen-hemoglobin dissociation curve as this athlete's training did?
ADecreased 2,3-bisphosphoglycerate
BIncreased carbon monoxide inhalation
CDecreased temperature
DDecreased pH
EIncreased partial pressure of oxygen
An investigator is studying the changes that occur in the oxygen-hemoglobin dissociation curve of different types of hemoglobin under various conditions. The blood obtained from a male infant shows decreased affinity for 2,3-bisphosphoglyceric acid. Which of the following is the most likely composition of the hemoglobin molecule in this sample?
Aα2βS2
Bα2β2
Cα2δ2
Dα2γ2
Eβ4
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