The chemical reactions and pathways leading to the formation of tetrapyrroles, natural pigments containing four pyrrole rings joined by one-carbon units linking position 2 of one pyrrole ring to position 5 of the next. [ GOC:mah ]
Synonyms: tetrapyrrole formation tetrapyrrole biosynthesis tetrapyrrole synthesis tetrapyrrole anabolism
This is just here as a test because I lose it