( Cell ( ( ( ( membrane functions ) ( as ( a barrier ) ) ) ( to ( ( the movement ) ( of ( ( ( substances ( between ( the intracellular ) ) ) and ) ( ( extracellular spaces ) 3 ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Cell)) (VP (VBD membrane) (NP (NNS functions)) (PP (IN as) (NP (DT a) (NN barrier))) (PP (TO to) (NP (NP (DT the) (NN movement)) (PP (IN of) (NP (NP (NP (NNS substances)) (PP (IN between) (NP (DT the) (NN intracellular)))) (CC and) (NP (NP (NN extracellular) (NNS spaces)) (NP (CD 3)))))))) (. .)))
Cell membrane functions as a barrier to the movement of substances between the intracellular and extracellular spaces 3.
(ROOT (S (NP (NP (DT A) (NN cell) (POS 's)) (NN membrane)) (VP (VBZ provides) (NP (DT a) (NN barrier) (S (VP (TO to) (VP (VB keep) (NP (NN extracellular) (NNS materials)) (PP (IN from) (S (VP (VBG mixing) (PP (IN with) (NP (PRP$ its) (JJ internal) (NNS components))))))))))) (. .)))