CO binds more strongly to the heme iron than O₂ does due to which reason? A) CO binds to the heme iron perpendicular to the porphyrin ring, allowing maximum electron orbital overlap between CO and Fe²⁺. B) CO weighs less than O₂, therefore binding to the heme iron more easily. C) CO binds to the heme iron covalently, while O₂ binds via ionic interactions. D) All of the answers are correct. E) None of the answers is correct.

Question

Quizplus · Accepted Answer

CO binds to the heme iron perpendicular to the porphyrin ring, allowing maximum electron orbital overlap between CO and Fe²⁺. This increases the strength of the bond between CO and the heme iron. The weight of the molecule and the type of bond (covalent or ionic) are not the determining factors for the strength of the bond. Therefore, options B, C, D, and E are incorrect.

CO Binds More Strongly to the Heme Iron Than O2

CO Binds More Strongly to the Heme Iron Than O₂