( ( ( Tyr Tyrosine ) ( -LRB- ( ( an ( amino acid ) ) -RRB- ) ) ) . )
(ROOT (NP (NP (NNP Tyr) (NNP Tyrosine)) (PRN (-LRB- -LRB-) (NP (DT an) (JJ amino) (NN acid)) (-RRB- -RRB-)) (. .)))
Tyr Tyrosine (an amino acid ).
(ROOT (S (NP (NNS Catecholamines)) (VP (VBP are) (NP (NP (DT a) (NN class)) (PP (IN of) (NP (JJ amine) (NNS hormones))) (SBAR (WHNP (WHNP (DT that)) (NP (WRB when) (JJ synthesised))) (S (VP (VBP form) (NP (DT the) (JJ amino) (NN acid) (NN tyrosine))))))) (. .)))