These heme like substances theoretically inhibit ALA synthase and hence the accumulation of toxic precursors.

The holoprotein (protein heme cofactor) is widely believed to be a product of both plant and the bacterium in which the apoprotein is produced by the plant and the heme (an iron atom bound in a porphyrin ring) is produced by the bacterium.

For example, haptoglobin tightly binds to hemoglobin subunits, while hemopexin captures the heme when the hemoglobin releases it.

Heme Arginate (NormoSang) is used during crises but also in preventive treatment to avoid crises, one treatment every 10 days.

In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change of the molecule when hit by light.

MPO has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus.

Buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, due to the heme containing enzyme myeloperoxidase that they produce.