or chiefly Brit  hae*mo*glo*bin  n 1  :  an iron-containing respiratory pigment of vertebrate red blood cells that functions primarily in the transport of oxygen from the lungs to the tissues of the body, that consists of four polypeptide chains designated alpha, beta, gamma, and delta each of which is linked to a heme molecule, that combines loosely and reversibly with oxygen in the lungs or gills to form oxyhemoglobin and with carbon dioxide in the tissues to form carbhemoglobin, that in humans is present normally in blood to the extent of 14 to 16 grams in 100 milliliters expressed sometimes on a scale of 0 to 100 with an average normal value (as 15 grams) taken as 100, and that is determined in blood either colorimetrically or by quantitative estimation of the iron present - see FETAL HEMOGLOBIN  - compare CARBOXYHEMOGLOBIN METHEMOGLOBIN   2  :  any of numerous iron-containing respiratory pigments of invertebrates and some plants (as yeasts) he*mo*glo*bin*ic or chiefly Brit  hae*mo*glo*bin*ic  adj he*mo*glo*bi*nous or chiefly Brit  hae*mo*glo*bi*nous  adj 
 
 
 
Similar sounding terms:  hemoglobin A 
 
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