( Enzymes ( ( are ( proteins ( that ( act ( as ( ( organic catalysts ) ( to ( ( speed ( chemical reactions ) ) ( within cells ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Enzymes)) (VP (VBP are) (NP (NP (NNS proteins)) (SBAR (WHNP (WDT that)) (S (VP (VBP act) (SBAR (IN as) (S (NP (JJ organic) (NNS catalysts)) (VP (TO to) (VP (VB speed) (NP (NN chemical) (NNS reactions)) (PP (IN within) (NP (NNS cells)))))))))))) (. .)))
Enzymes are proteins that act as organic catalysts to speed chemical reactions within cells.
(ROOT (S (PP (IN In) (NP (DT a) (JJ biological) (NN reaction))) (, ,) (NP (NNS proteins)) (VP (VBP act) (PP (IN as) (NP (NNS catalysts)))) (. .)))