Ranasinghe,Chandani2026-10-062026-10-062025-09https://dr.ichemc.ac.lk/handle/123456789/556Guest Articles Page 22-27Well-known tetrapyrroles include hemes, which impart the red colour to blood and facilitate oxygen transport; chlorophylls, the central pigments of photosynthesis in plants, algae and cyanobacteria; and cobalamin (vitamin B₁₂), an essential micronutrient in human metabolism. Others, such as siroheme, coenzyme F430, heme d1, and bilins, are equally significant across different biological contexts.1enTetrapyrrolesmoleculeslifeArticle