glycine vs amino acid

glycine and amino acid both are nouns.

Word	Noun	Adjective	Verb	Adverb
glycine	Yes	No	No	No
amino acid	Yes	No	No	No

As nouns, amino acid is a hypernym of glycine; that is, amino acid is a word with a broader meaning than glycine:

glycine: the simplest amino acid found in proteins and the principal amino acid in sugar cane
amino acid: organic compounds containing an amino group and a carboxylic acid group

Other hypernyms of glycine include aminoalkanoic acid.

glycine (noun)	amino acid (noun)
the simplest amino acid found in proteins and the principal amino acid in sugar cane	organic compounds containing an amino group and a carboxylic acid group