myoglobin

The oxygen-carrying and storage protein of muscle, resembling blood hemoglobin in function but containing only one subunit and one heme as part of the molecule (rather than the four of hemoglobin), and with a molecular weight approximately one-quarter that of hemoglobin. SYN: muscle hemoglobin, myohemoglobin. [myo- + hemoglobin]

- carbonmonoxy m. SYN: carboxyhemoglobin.

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myo·glo·bin .mī-ə-'glō-bən, 'mī-ə-. n a red iron-containing protein pigment in muscles that is similar to hemoglobin but differs in the globin portion of its molecule, in the smaller size of its molecule (as in the mammalian heart muscle which has only one fourth the molecular weight of the hemoglobin in the blood of the same animal), in its greater tendency to combine with oxygen, and in its absorption of light at longer wavelengths called also myohemoglobin

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n.

see myohaemoglobin

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myo·glo·bin (Mb) (miґo-glo″bin) the oxygen-transporting pigment of muscle, a type of hemoprotein resembling a single subunit of hemoglobin, composed of one globin polypeptide chain and one heme group (containing one iron atom); it combines with oxygen released by erythrocytes, stores it, and transports it to the mitochondria of muscle cells, where it generates energy by combustion of glucose to carbon dioxide and water.