( ( Chemical reactions ) ( also ( ( involve ( ( bond ( ( breaking and ) bond ) ) forming ) ) . ) ) )
(ROOT (S (NP (NNP Chemical) (NNS reactions)) (ADVP (RB also)) (VP (VBP involve) (NP (NP (NN bond) (NN breaking) (CC and) (NN bond)) (VP (VBG forming)))) (. .)))
Chemical reactions also involve bond breaking and bond forming.
(ROOT (S (NP (JJ Catabolic) (NNS reactions)) (VP (VBP involve) (S (VP (VBG breaking) (NP (NNS bonds))))) (. .)))