( Hormones ( ( ( ( ( ( act ( as ( chemical messengers ) ) ) , ) ( ( traveling ( through ( the blood ) ) ) ( to ( distant ( ( tissues and ) organs ) ) ) ) ) , ) ( where ( they ( can ( bind ( to ( ( specific ( cell sites ) ) ( called receptors ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Hormones)) (VP (VBP act) (PP (IN as) (NP (NN chemical) (NNS messengers))) (, ,) (S (VP (VBG traveling) (PP (IN through) (NP (DT the) (NN blood))) (PP (TO to) (NP (JJ distant) (NNS tissues) (CC and) (NNS organs))))) (, ,) (SBAR (WHADVP (WRB where)) (S (NP (PRP they)) (VP (MD can) (VP (VB bind) (PP (TO to) (NP (NP (JJ specific) (NN cell) (NNS sites)) (VP (VBN called) (NP (NNS receptors)))))))))) (. .)))
Hormones act as chemical messengers, traveling through the blood to distant tissues and organs, where they can bind to specific cell sites called receptors.
(ROOT (S (NP (NP (NNS Receptors)) (PP (IN for) (NP (NNS hormones)))) (VP (VP (VBP recognize) (NP (NNS molecules)) (PP (IN with) (NP (JJ specific) (NNS shapes) (CC and) (NN side) (NNS groups)))) (, ,) (CC and) (VP (VBP respond) (ADVP (RB only)) (PP (TO to) (NP (NP (DT those)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (VP (VBN recognized))))))))) (. .)))