Hemoglobins

Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers an animal's metabolism. A healthy human has 12to 20grams of hemoglobin in every 100mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and a globulin.

form of haemoglobin chemically linked to a sugar

thumbnail|right|The structure of cytochrome b5 reductase, the enzyme that converts methemoglobin to hemoglobin.

thumb|upright=1.35|Leghemoglobin A from a soybean (PDB: 1BIN)

Carboxyhemoglobin (carboxyhaemoglobin BrE) (symbol COHb or HbCO, also known as carbonylhemoglobin) is a stable complex of carbon monoxide and hemoglobin (Hb) that forms in red blood cells upon contact with carbon monoxide. Carboxyhemoglobin is often mistaken for the compound formed by the combination of carbon dioxide (carboxyl) and hemoglobin, which is actually carbaminohemoglobin. Carboxyhemoglobin terminology emerged when carbon monoxide was known by its historic name, "carbonic oxide", and evolved through Germanic and British English etymological influences; the preferred IUPAC nomenclatur

protein complex

instance of defined set in Homo sapiens with Reactome ID (R-HSA-2168876)

mammalian protein found in Homo sapiens

thumb|Binding of carbon dioxide to hemoglobin to form carbaminohemoglobin Carbaminohemoglobin (carbaminohaemoglobin BrE) (CO2Hb, also known as carbheamoglobin and carbohemoglobin) is a compound of hemoglobin and carbon dioxide, and is one of the forms in which carbon dioxide exists in the blood. In blood, 23% of carbon dioxide is carried this way, while 70% is converted into bicarbonate by carbonic anhydrase and then carried in plasma, and 7% carried as free CO2, dissolved in plasma.

Human disease

variant of hemoglobin A

Sulfhemoglobinemia is a rare condition in which there is excess sulfhemoglobin (SulfHb) in the blood. The pigment is a greenish derivative of hemoglobin which cannot be converted back to normal, functional hemoglobin. It causes cyanosis even at low blood levels.

protein-coding gene in the species Homo sapiens

abnormal type of hemoglobin that consists of four gamma globins

chemical compound

Hemoglobin subunit gamma-2 is a protein that in humans is encoded by the HBG2 gene.