( ( Chains ( of ( ( amino acids ) ( synthesized ( by ( living systems ) ) ) ) ) ) ( ( are ( called ( ( ( polypeptides ( -LRB- ( ( up ( to ( ( about 50 ) ( amino acids ) ) ) ) -RRB- ) ) ) and ) ( proteins ( -LRB- ( ( ( more ( ( than 50 ) amino ) ) acids ) -RRB- ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Chains)) (PP (IN of) (NP (NP (JJ amino) (NNS acids)) (VP (VBN synthesized) (PP (IN by) (NP (VBG living) (NNS systems))))))) (VP (VBP are) (VP (VBN called) (NP (NP (NP (NNS polypeptides)) (PRN (-LRB- -LRB-) (ADVP (RB up) (PP (TO to) (NP (QP (RB about) (CD 50)) (JJ amino) (NNS acids)))) (-RRB- -RRB-))) (CC and) (NP (NP (NNS proteins)) (PRN (-LRB- -LRB-) (NP (QP (JJR more) (IN than) (CD 50) (CD amino)) (NNS acids)) (-RRB- -RRB-)))))) (. .)))
Chains of amino acids synthesized by living systems are called polypeptides (up to about 50 amino acids) and proteins (more than 50 amino acids).
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (JJ amino) (NNS acids)) (VP (VBZ bind) (ADVP (RB together))))) (, ,) (NP (PRP they)) (VP (VBP form) (SBAR (S (NP (DT a) (JJ long) (NN chain)) (VP (VBD called) (NP (NP (DT a) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NN polypeptide)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (NP (DT an) (JJ essential) (NN component)) (PP (IN of) (NP (NN protein)))))))))))) (. .)))