( ( Catalysts ( that ( slow ( the reaction ) ) ) ) ( ( ( ( ( are ( called ( negative catalysts ) ) ) , ) or ) inhibitors ) . ) )
(ROOT (S (NP (NP (NNS Catalysts)) (SBAR (WHNP (WDT that)) (S (VP (VB slow) (NP (DT the) (NN reaction)))))) (VP (VP (VBP are) (VP (VBN called) (NP (JJ negative) (NNS catalysts)))) (, ,) (CC or) (VP (VBZ inhibitors))) (. .)))
Catalysts that slow the reaction are called negative catalysts, or inhibitors.
(ROOT (S (SBAR (IN If) (S (NP (DT a) (NN catalyst)) (VP (VBZ runs) (PRT (RP out))))) (, ,) (NP (DT the) (NN reaction)) (VP (VBZ slows)) (. .)))