what is the 20 amino acids?
['Alanine – ala – A.', 'Arginine – arg – R.', 'Asparagine – asn – N.', 'Aspartic acid – asp – D.', 'Cysteine – cys – C.', 'Glutamine – gln – Q.', 'Glutamic acid – glu – E.', 'Glycine – gly – G.']