( Enzymes ( ( serve ( as ( ( biochemical catalysts ) ( that ( ( speed up ) ( ( normal ( chemical reactions ) ) ( in cells ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Enzymes)) (VP (VBP serve) (PP (IN as) (NP (NP (JJ biochemical) (NNS catalysts)) (SBAR (WHNP (WDT that)) (S (VP (VB speed) (PRT (RP up)) (NP (NP (JJ normal) (NN chemical) (NNS reactions)) (PP (IN in) (NP (NNS cells)))))))))) (. .)))
Enzymes serve as biochemical catalysts that speed up normal chemical reactions in cells.
(ROOT (S (NP (NNS Enzymes)) (VP (VP (VB speed) (PRT (RP up)) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (DT a) (JJ specific) (NN chemical) (NN reaction))))) (CC and) (VP (VBP are) (ADVP (RB therefore)) (VP (VBN known) (PP (IN as) (NP (JJ biochemical) (NNS catalysts)))))) (. .)))