| hemoglobin | <cell biology, haematology> Four subunit globular oxygen carrying protein of the erythrocytes of vertebrates and some invertebrates. It is a conjugated protein containing four haem groups and globin. There are two alpha and two beta chains (very similar to myoglobin) in adult humans, the haem moiety (an iron containing substituted porphyrin) is firmly held in a nonpolar crevice in each peptide chain. There are four globin polypeptide chains, designated alpha, beta, gamma, delta in the adult. Each is composed of several hundred amino acids. (08 Mar 2000) |
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| hemoglobinometer | <physiology> Same as Haemochromometer. Source: Websters Dictionary (01 Mar 1998) |
| hemoglobinopathy | <disease, haematology> Disorder due to abnormalities in the haemoglobin molecule, the best known being sickle cell anaemia in which there is a single amino acid substitution (valine for glutamate) in position 6 of the beta chain. In other cases one of the globin chains is synthesised at a slower rate, despite being normal in structure. See: thalassaemia. Origin: Gr. Pathos = disease (18 Nov 1997) |