Hb vs hemoprotein

Hb and hemoprotein both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hb	Yes	No	No	No
hemoprotein	Yes	No	No	No

As nouns, hemoprotein is a hypernym of Hb; that is, hemoprotein is a word with a broader meaning than Hb:

Hb: a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues
hemoprotein: a conjugated protein linked to a compound of iron and porphyrin

Other hypernyms of Hb include haemoprotein.

Hb (noun)	hemoprotein (noun)
a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues	a conjugated protein linked to a compound of iron and porphyrin