noun
also hae·mo·glo·bin ˈ ̷ ̷ ̷ ̷ˌglōbə̇n, ˌ ̷ ̷ ̷ ̷ˈ ̷ ̷ ̷ ̷
( -s )
Etymology: International Scientific Vocabulary, short for earlier hematoglobulin, from hemato- (from hematin ) + globulin
1.
a. : an iron-containing protein pigment occurring in the red blood cells of vertebrates and functioning primarily in the transport of oxygen from the lungs to the tissues of the body
b. : the dark purplish crystallizable form of this pigment that is found chiefly in the venous blood of vertebrates, that is a conjugated protein composed of heme and globin commonly in a ratio of four molecules of heme to one of globin but that may vary somewhat in different species and in different physiological and pathological states (as in some anemias), 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 man is present normally in blood to the extent of 14 to 16 gm. in 100 ml. expressed sometimes on a scale of 0 to 100 with an average normal value (as 15 gm.) taken as 100, and that is determined in blood either colorimetrically or by quantitative estimation of the iron present — symbol Hb ; called also ferrohemoglobin, reduced hemoglobin ; compare carbonylhemoglobin , methemoglobin
c. : any of numerous chemically similar iron-containing respiratory pigments that occur in cells or usually free in the plasma of many annelid worms and certain other invertebrates, in some yeasts and other fungi, in the nodules formed on the roots of leguminous plants by nitrogen-fixing bacteria, and elsewhere — compare hemoprotein
2. : any of various respiratory pigments consisting of a conjugated protein that has as the nonprotein group either heme or an analogous compound containing a metal — compare myoglobin
• he·mo·glo·bin·ic | ̷ ̷ ̷ ̷ˌglō|binik adjective
• he·mo·glo·bi·nous | ̷ ̷ ̷ ̷|glōbənəs adjective