myoglobin vs hemoprotein

myoglobin and hemoprotein both are nouns.

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

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

myoglobin: a hemoprotein that receives oxygen from hemoglobin and stores it in the tissues until needed
hemoprotein: a conjugated protein linked to a compound of iron and porphyrin

Other hypernyms of myoglobin include haemoprotein.

myoglobin (noun)	hemoprotein (noun)
a hemoprotein that receives oxygen from hemoglobin and stores it in the tissues until needed	a conjugated protein linked to a compound of iron and porphyrin