porphyrin

[NHolmes3L]

What do we need to know about porphyrin?

[Kendall 3H]

I think we just need to know that its the ligand that finds with fe to make a heme complex and that it is tetradenate.

[Chris Tai 1B]

A porphyrin ring is one that completely surrounds an atom (like a transition metal) and often forms coordinate covalent bonds with it. For instance, in the heme complex, the iron metal atom is surrounded by a porphyrin ring, where four different nitrogen atoms form coordinate covalent bonds with it. Porphyrin ligands like this one are tetradentate

[zachary_nhem_4I]

Adding to Chris, a heme complex binds with a protein and oxygen to make a myoglobin, and four myoglobin make a hemoglobin.