haemitin vs haem

haemitin and haem both are nouns.

Word	Noun	Adjective	Verb	Adverb
haemitin	Yes	No	No	No
haem	Yes	No	No	No

As nouns, haemitin and haem are synonyms defined as:

haemitin and haem: a complex red organic pigment containing iron and other atoms to which oxygen binds

Other synonyms of haemitin include hematin, heme, protoheme.

haemitin (noun)	haem (noun)
a complex red organic pigment containing iron and other atoms to which oxygen binds	a complex red organic pigment containing iron and other atoms to which oxygen binds