( ( ( ( cell membranes ) and ) ( membrane ( transport mechanisms ) ) ) ; )
(ROOT (NP (NP (NP (NN cell) (NNS membranes)) (CC and) (NP (JJ membrane) (NN transport) (NNS mechanisms))) (: ;)))
cell membranes and membrane transport mechanisms;
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS substances)) (VP (VBP pass) (PP (IN through) (NP (DT the) (NN cell) (NN membrane))) (PP (IN without) (S (VP (VBG needing) (NP (DT any) (NN energy)))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (JJ passive) (NN transport)))) (. .)))