( ( Phenylalanine ( Tyrosine ( Tryptophan ( Proline Next ) ) ) ) ( we ( ( ( have ( 2 ( amino acids ) ) ) ( ( ( ( ( with ( acidic sidechains ) ) , ) and ) ( 2 more ) ) ( with ( ( ( half-acidic and ) half-aminic ) sidechains ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Phenylalanine) (NNP Tyrosine) (NNP Tryptophan) (NNP Proline) (NNP Next)) (NP (PRP we)) (VP (VBP have) (NP (CD 2) (JJ amino) (NNS acids)) (PP (PP (IN with) (NP (JJ acidic) (NNS sidechains))) (, ,) (CC and) (ADVP (NP (CD 2)) (RBR more)) (PP (IN with) (NP (ADJP (JJ half-acidic) (CC and) (JJ half-aminic)) (NNS sidechains))))) (. .)))
Phenylalanine Tyrosine Tryptophan Proline Next we have 2 amino acids with acidic sidechains, and 2 more with half-acidic and half-aminic sidechains.
(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))))))) (. .)))