What is the chemical nature of the heme group found in hemoglobin?

Explanation

The heme group in hemoglobin is specifically a protoporphyrin IX molecule, which binds iron and facilitates oxygen transport. While it is situated between helices C and D and surrounded by a nonpolar environment, its chemical identity is protoporphyrin IX. It is not directly bonded to the E7 histidine; instead, the proximal histidine (F8) coordinates the iron atom.