( ( These ( two buttons ) ) ( ( precede ( each ( polypeptide chain ) ) ) . ) )
(ROOT (S (NP (DT These) (CD two) (NNS buttons)) (VP (VB precede) (NP (DT each) (JJ polypeptide) (NN chain))) (. .)))
These two buttons precede each polypeptide chain.
(ROOT (S (NP (NNP Insulin)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (CD two) (JJ polypeptide) (NNS chains))))) (. .)))