( Proteins ( ( are ( ( large ( biological molecules ) ) ( made ( of ( subunits ( called ( ( amino acids ) ( that ( are ( ( ( ( attached ( to ( one another ) ) ) ( in chains ) ) , ) ( like ( ( the cars ) ( of ( a train ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNPS Proteins)) (VP (VBP are) (NP (NP (JJ large) (JJ biological) (NNS molecules)) (VP (VBN made) (PP (IN of) (NP (NP (NNS subunits)) (VP (VBN called) (NP (NP (JJ amino) (NNS acids)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (VP (VBN attached) (PP (TO to) (NP (CD one) (DT another))) (PP (IN in) (NP (NNS chains))) (, ,) (PP (IN like) (NP (NP (DT the) (NNS cars)) (PP (IN of) (NP (DT a) (NN train)))))))))))))))) (. .)))
Proteins are large biological molecules made of subunits called amino acids that are attached to one another in chains, like the cars of a train.
(ROOT (S (NP (DT A) (NN protein)) (VP (VBZ is) (NP (NP (DT an) (JJ organic) (NN compound)) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (NP (JJ small) (NNS molecules)) (VP (VBN called) (NP (JJ amino) (NNS acids)))))))) (. .)))