NOTICE: Citizendium is still being set up on its newer server, treat as a beta for now; please see here for more.
Citizendium - a community developing a quality comprehensive compendium of knowledge, online and free. Click here to join and contribute—free
CZ thanks our previous donors. Donate here. Treasurer's Financial Report -- Thanks to our content contributors. --


From Citizendium, the Citizens' Compendium
Revision as of 23:57, 28 December 2009 by Howard C. Berkowitz (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
This article is developing and not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.

In biology, hemoglobin is the "oxygen-carrying pigments of erythrocytes. They are found in all vertebrates and some invertebrates. The structure of the globin moiety differs between species."[1]

Human hemoglobins


The normal human embryo hemoglobin has two ζ-chains and two ε-chains.


In human fetuses the normal hemoglobin is Hemoglobin F (also called Hemoglobin F). Hemoglobin F has "two alpha and two gamma polypeptide subunits in comparison to normal adult hemoglobin, which has two alpha and two beta polypeptide subunits. Fetal hemoglobin concentrations can be elevated (usually above 0.5%) in children and adults affected by leukemia and several types of anemia."[2]


The normal adult human hemoglobin is Hemoglobin A. This hemoglobin consists of two alpha and two beta chains.[3] A less common hemoglobin found in normal adults is Hemoglobin A2. Hemoglobin A2 is an "adult hemoglobin component normally present in hemolysates from human erythrocytes in concentrations of about 3%. The hemoglobin is composed of two alpha chains and two delta chains. The percentage of HbA2 varies in some hematologic disorders, but is about double in beta-thalassemia."[4]


Normal hemoglobins

Most humans carry:[5]

  • "two α-globin genes on chromosome 16"
  • "two γ-globin genes on chromosome 11"
  • "a single δ-globin gene, and a single β-gene on chromosome 11"


  1. Anonymous (2019), Hemoglobin (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. Anonymous (2019), Hemoglobin F (English). Medical Subject Headings. U.S. National Library of Medicine.
  3. Anonymous (2019), Hemoglobin A (English). Medical Subject Headings. U.S. National Library of Medicine.
  4. Anonymous (2019), Hemoglobin A2 (English). Medical Subject Headings. U.S. National Library of Medicine.
  5. Attar EC, Hasserjian RP (May 2006). "Case records of the Massachusetts General Hospital. Case 14-2006. A 25-year-old woman with anemia and iron overload". The New England journal of medicine 354 (19): 2047–56. DOI:10.1056/NEJMcpc069005. PMID 16687718. Research Blogging.