CO Binds More Strongly to the Heme Iron Than O₂

question 16

Multiple Choice

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.

---

Definitions:

US Dollar

The official currency of the United States, widely used as a benchmark and reserve currency around the world.

Canadian Dollar

The official currency of Canada, often symbolized as CAD and colloquially referred to as the "loonie."

Spot Market

A marketplace for the immediate settlement of transactions involving commodities or securities.

Interest Rate Parity

Holds that investors should expect to earn the same return in all countries after adjusting for risk.