| English |
| heme |
  |
|
| Attestation |
3
|
| Part of speech |
Noun
|
| Grammatical label |
Countable
|
| Variant |
Heme group
|
| Definition |
Hemoglobin synthesis requires the coordinated production of heme and globin. Heme is the prosthetic group that mediates reversible binding of oxygen by hemoglobin. It is synthesized in a complex series of steps involving enzymes in the mitochondrion and in the cytosol of the cell. The first step in heme synthesis takes place in the mitochondrion, with the condensation of succinyl CoA and glycine by ALA synthase to form 5-aminolevulic acid (ALA). This molecule is transported to the cytosol where a series of reactions produce a ring structure called coproporphyrinogen III. This molecule returns to the mitochondrion where an addition reaction produces protoporhyrin.
|
| Definition source |
Joint Center for Sickle Cell and Thalassemic Disorders. Thalassemia Overview. (INTEEN05)
|
| Context |
The sythesis of heme is a complex process that involves multiple enzymatic steps. The process begins in the mitochondrion with the condensation of succinyl-CoA and glycine to form 5-aminolevulinic acid. A series of steps in the cytoplasm produce coproporphrynogen III, which re-enters the mitochondrion. The final enzymatic steps produce heme. The enzyme ferrochelatase inserts iron into the ring structure of protoporphyrin IX to produce heme. Deranged production of heme produces a variety of anemias.
|
| Context source |
Joint Center for Sickle Cell and Thalassemic Disorders. Thalassemia Overview. (INTEEN05)
|
| Figure source |
http://omlc.ogi.edu/spectra/hemoglobin/hemestruct/
|
| Synonym |
Prosthetic group
|
| Subject field |
Haemopoiesis
|
| Comprehensive concept |
Hemoglobin
|
| Partitive concept |
Iron
|
| Related concept |
Globin chain, haemopoiesis
|
| it |
Eme
|
| Reliability code |
3
|
