( ( ( ( ( ( Presynaptic cells ) ( will ( produce ( specific ( neurotransmitter molecules ) ) ) ) ) , ) and ) ( ( these ( neurotransmitter molecules ) ) ( will ( be ( stored ( in ( ( sac-like structures ) ( called vesicles ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Presynaptic) (NNS cells)) (VP (MD will) (VP (VB produce) (NP (JJ specific) (NN neurotransmitter) (NNS molecules))))) (, ,) (CC and) (S (NP (DT these) (NN neurotransmitter) (NNS molecules)) (VP (MD will) (VP (VB be) (VP (VBN stored) (PP (IN in) (NP (NP (JJ sac-like) (NNS structures)) (VP (VBN called) (NP (NNS vesicles))))))))) (. .)))
Presynaptic cells will produce specific neurotransmitter molecules, and these neurotransmitter molecules will be stored in sac-like structures called vesicles .
(ROOT (S (NP (NNS Vesicles)) (VP (VBP are) (VP (VBN used) (PP (IN during) (NP (NNS endocytosis))) (S (VP (TO to) (VP (VB allow) (S (NP (NNS molecules)) (VP (TO to) (VP (VB enter) (NP (DT the) (NN cell)))))))))) (. .)))