haemoprotein vs Hb

haemoprotein and Hb both are nouns.

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

As nouns, Hb is a hyponym of haemoprotein; that is, Hb is a word with a more specific, narrower meaning than haemoprotein:

haemoprotein: a conjugated protein linked to a compound of iron and porphyrin
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

Other hyponyms of haemoprotein include haemoglobin, hemoglobin, myoglobin, cytochrome.

haemoprotein (noun)	Hb (noun)
a conjugated protein linked to a compound of iron and porphyrin	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