Question

What is the coordination number of iron in the heme group of myoglobin?

Answer 1

The coordination number of iron in the heme group of myoglobin is 6. In the heme group, the iron atom is coordinated to four nitrogen atoms from the porphyrin ring, one nitrogen atom from the imidazole side chain of a histidine residue in the protein, and one oxygen atom from the bound oxygen molecule  O2 .