( ( ( An enzyme ) ( ( ( is ( a ( biological catalyst ) ) ) , ) i.e. ) ) ( , ( it ( ( ( ( speeds up ) ( ( the rate ) ( of ( a ( biochemical reaction ) ) ) ) ) ( without ( being ( consumed ( during ( ( the course ) ( of ( that reaction ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (DT An) (NN enzyme)) (VP (VBZ is) (NP (DT a) (JJ biological) (NN catalyst)) (, ,) (ADVP (RB i.e.)))) (, ,) (NP (PRP it)) (VP (VBZ speeds) (PRT (RP up)) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (DT a) (JJ biochemical) (NN reaction)))) (PP (IN without) (S (VP (VBG being) (VP (VBN consumed) (PP (IN during) (NP (NP (DT the) (NN course)) (PP (IN of) (NP (DT that) (NN reaction)))))))))) (. .)))
An enzyme is a biological catalyst, i.e., it speeds up the rate of a biochemical reaction without being consumed during the course of that reaction.
(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)))))) (. .)))