The book includes several topics as per Universities curriculum of [...]. and [...]. course work in Chemistry. This covers different Physiological aspects of Bioinorganic Chemistry in terms of 4 Chapters with in-depth and up-to-date coverage. The book symmetrically presents (i) Coordination chemistry of chlorophylls/bacteriochlophylls and its functional aspects in photosynthesis, (ii) Complexes containing nitric oxide: Synthesis, reactivity, structure, bonding, and therapeutic aspects of nitric oxide releasing molecules (NORMS) in human beings and plants, (iv) Complexes containing carbon monoxide: Synthesis, reactivity, structure, bonding, and therapeutic aspects of carbon monoxide releasing molecules (CORMS) in human beings and plants, and (iv) Advantageous role of gaseous signaling molecule, H2S: Hydrogen sulphide and their respective donors, in ophthalmic diseases and physiological implications in plants. At the end, three relevant topics are included as appendices for updating students and faculty members.