Question

The heme group of myoglobin A. contains ferric ion. B. is bound to the polypeptide chain exclusively by interactions between polar groups. C. binds oxygen in an allosteric manner. D. is identical to that of hemoglobin. E. is bound to the polypeptide chain exclusively by interactions between nonpolar groups.

Answer 1

• Myoglobin and hemoglobin are globular proteins which have oxygen delivery capacity.
• Both have a heme prosthetic group, within the hydrophobic cleft of the protein.
• Iron atom (ferrous state, Fe²⁺) is centrally bound to heme coordinately.
• Thus, Myoglobin has similar heme group as hemoglobin.
• Answer: D.