1. Letters to a Young Chemist
2. The heme group a non‐polypeptide prosthetic group consisting of the protoporphyrin IX and a central iron atom is present in myoglobin hemoglobin and many other proteins[3a] whose biological functions include the detection and transportation of diatomic gases chemical catalysis and electron transfer.
3. Chlorophyll is a chlorin pigment structurally similar to the protoporphyrin of hemoglobin whose coordinative pocket hosts a MgIIion. Chlorophylls are the most important light absorbing pigments in the thylakoid membranes.