Heme is which porphyrin:
The side chain groups in porphyrins may be arranged in four different structural configurations (I to IV). Only type I and type III series are found in nature and the porphyrins of type III series are not only more abundant but are also physiologically impoant in humans. Haem is a type III porphyrin.
Type I
Type II
Type III
Type IV
HAEM synth and porphyrias