porphyrin-containing compound biosynthetic process heme biosynthetic process GO:0006783 heme biosynthesis Reactome:R-HSA-189451 haem biosynthesis heme anabolism heme formation The chemical reactions and pathways resulting in the formation of heme, any compound of iron complexed in a porphyrin (tetrapyrrole) ring, from less complex precursors. heme synthesis haem biosynthetic process biological_process heme metabolic process pigment biosynthetic process