Why does myoglobin have a histidine that prevents both O₂ and CO from binding perpendicularly to the heme plane? A) This increases myoglobin's affinity for O₂. B) This increases myoglobin's affinity for CO. C) This lessens the difference in myoglobin's affinity for CO versus O₂. D) This prevents the iron of the heme from being oxidized.

Question

Quizplus · Accepted Answer

The histidine in myoglobin ensures that both oxygen (O2) and carbon monoxide (CO) do not bind perpendicularly to the heme plane, which lessens the difference in myoglobin's affinity for these two gases, making it preferentially bind oxygen over carbon monoxide.

Why Does Myoglobin Have a Histidine That Prevents Both O2

Why Does Myoglobin Have a Histidine That Prevents Both O₂