Melvin Calvin vs chemist

Melvin Calvin and chemist both are nouns.

Word	Noun	Adjective	Verb	Adverb
Melvin Calvin	Yes	No	No	No
chemist	Yes	No	No	No

Melvin Calvin (noun)	chemist (noun)
United States chemist noted for discovering the series of chemical reactions in photosynthesis (1911-)	a scientist who specializes in chemistry
	a health professional trained in the art of preparing and dispensing drugs