Heme - Definition

Ask a question


Heme is a chemical term used for a structure containing an iron atom. This element is a component of hemoglobin, responsible for transporting oxygen between the lungs and organs, considering that the O2 molecule binds to this atom during blood oxygenation. This is why a heme is considered an essential cofactor of hemoglobin. A heme's structure is called a porphyrin, composed of four nuclei containing one nitrogen atom and four carbon atoms.