( ( During ( passive transport ) ) ( , ( molecules ( ( ( ( move naturally ) ( through ( ( a ( semi-permeable membrane ) ) ( from ( a ( high ( concentration area ) ) ) ) ) ) ) ( to ( a ( low ( concentration area ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN During) (NP (JJ passive) (NN transport))) (, ,) (NP (NNS molecules)) (VP (VBP move) (ADVP (RB naturally)) (PP (IN through) (NP (NP (DT a) (JJ semi-permeable) (NN membrane)) (PP (IN from) (NP (DT a) (JJ high) (NN concentration) (NN area))))) (PP (TO to) (NP (DT a) (JJ low) (NN concentration) (NN area)))) (. .)))
During passive transport , molecules move naturally through a semi-permeable membrane from a high concentration area to a low concentration area.
(ROOT (S (NP (NNP Passive) (NN transport)) (VP (VP (VBZ requires) (NP (DT no) (NN energy))) (CC and) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (NNS substances)) (VP (VBP move) (PP (IN from) (NP (NP (NNS areas)) (PP (IN of) (NP (NP (JJR higher)) (PP (TO to) (NP (JJR lower) (NN concentration)))))))))))) (. .)))