by Scott Prahl

A model of heme.

heme structure The Merk index says,

"mol. wt. 616.48 C34H32FeN4O4; It is the color furnishing portion of hemoglobin. Absorption max in phosphate buffer at ph 7 is ~550, 575 nm. Sparingly soluble in glacial acetic acid; freely soluble in presence of oxygen. Very unstable."

Heme is very similar to protoporphyrin IX. See below. heme-structure protoporphyrin IX structure