( ( ( ( ( ( ( ( ( the ( cell biology ) ) ( of ( second messengers ) ) ) , ) ( plasma membrane ) ) , ) ( membrane transport ) ) , ) ( ( cell-to-cell signalling ) ( by ( ( hormones and ) receptors ) ) ) ) . )
(ROOT (NP (NP (DT the) (NN cell) (NN biology)) (PP (IN of) (NP (JJ second) (NNS messengers))) (, ,) (NP (NN plasma) (NNS membrane)) (, ,) (NP (JJ membrane) (NN transport)) (, ,) (NP (NP (JJ cell-to-cell) (NN signalling)) (PP (IN by) (NP (NNS hormones) (CC and) (NNS receptors)))) (. .)))
the cell biology of second messengers, plasma membrane, membrane transport, cell-to-cell signalling by hormones and receptors.
(ROOT (S (NP (NNP Passive) (NN transport)) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (NNS substances)) (VP (VBP cross) (NP (DT the) (NN plasma) (NN membrane)) (PP (IN without) (NP (NP (DT any) (NN input)) (PP (IN of) (NP (NN energy))))) (PP (IN from) (NP (DT the) (NN cell))))))) (. .)))