Which part of the hemoglobin molecule binds carbon dioxide for transport?

• A. The heme group
• B. The iron atom
• C. The globin protein chains
• D. The oxygen-binding site

Answer: (C)

Verified step by step guidance

1. Understand the structure of hemoglobin: Hemoglobin is a protein composed of four subunits, each containing a heme group and a globin protein chain.
2. Identify the role of the heme group: The heme group contains an iron atom that primarily binds oxygen for transport in the blood.
3. Recognize the function of the globin protein chains: These chains are responsible for binding carbon dioxide. CO2 binds to the amino groups of the globin chains, forming carbaminohemoglobin.
4. Differentiate between the binding sites: The oxygen-binding site is located at the iron atom within the heme group, while carbon dioxide binds to the globin protein chains.
5. Conclude that the globin protein chains are the part of the hemoglobin molecule that binds carbon dioxide for transport.