haem vs haemitin

haem and haemitin both are nouns.

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

As nouns, haem and haemitin are synonyms defined as:

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

Other synonyms of haem include hematin, heme, protoheme.

haem (noun)	haemitin (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