( Proteins ( ( act ( as ( ( enzymes , ) ( which ( ( are catalysts ) ( involved ( in ( all ( biological reactions ) ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (NNPS Proteins)) (VP (VBP act) (PP (IN as) (NP (NP (NNS enzymes)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (ADVP (RB catalysts)) (VP (VBN involved) (PP (IN in) (NP (DT all) (JJ biological) (NNS reactions)))))))))) (: ;)))
Proteins act as enzymes, which are catalysts involved in all biological reactions;
(ROOT (S (PP (IN In) (NP (DT a) (JJ biological) (NN reaction))) (, ,) (NP (NNS proteins)) (VP (VBP act) (PP (IN as) (NP (NNS catalysts)))) (. .)))