When O₂ binds to heme in hemoglobin, the ____ ion is drawn into the plane of the ____ causing a conformational change that is transmitted to adjacent subunits enhancing the ____ for additional O₂ binding. A) Mg²⁺; globin; planarity B) Fe³⁺; heme; folding C) Mg²⁺; globin; attraction D) Fe³⁺; porphyrin; affinity E) Fe²⁺; porphyrin; affinity

Question

Quizplus · Accepted Answer

When O₂ binds to heme in hemoglobin, it binds to the Fe (iron) ion in the porphyrin ring, not Mg (magnesium). The binding of O₂ to the Fe ion causes a conformational change in the heme molecule, which is transmitted to adjacent subunits and enhances the affinity for additional O₂ binding. Therefore, the correct answer is E) Fe²⁺; porphyrin; affinity.

When O2 Binds to Heme in Hemoglobin, the ____ Ion

When O₂ Binds to Heme in Hemoglobin, the ____ Ion