( ( ( ( ( ( The ( bacterial ( plasma membrane ) ) ) ( ( is also ) ( a ( permeability barrier ) ) ) ) , ) and ) ( it ( contains ( ( ( a variety ) ( of ( different ( transport proteins ) ) ) ) ( that ( selectively ( ( mediate ( ( the passage ) ( of substances ) ) ) ( ( ( into and ) out ) ( of ( the cell ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT The) (JJ bacterial) (NN plasma) (NN membrane)) (VP (VBZ is) (ADVP (RB also)) (NP (DT a) (JJ permeability) (NN barrier)))) (, ,) (CC and) (S (NP (PRP it)) (VP (VBZ contains) (NP (NP (DT a) (NN variety)) (PP (IN of) (NP (JJ different) (NN transport) (NNS proteins))) (SBAR (WHNP (WDT that)) (S (ADVP (RB selectively)) (VP (VB mediate) (NP (NP (DT the) (NN passage)) (PP (IN of) (NP (NNS substances)))) (PP (IN into) (CC and) (IN out) (PP (IN of) (NP (DT the) (NN cell)))))))))) (. .)))
The bacterial plasma membrane is also a permeability barrier, and it contains a variety of different transport proteins that selectively mediate the passage of substances into and out of the cell.
(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))))))) (. .)))