( ( membrane ( and ( ion channel ) ) ) ( biophysics . ) )
(ROOT (S (NP (NN membrane) (CC and) (NN ion) (NN channel)) (VP (VBZ biophysics)) (. .)))
membrane and ion channel biophysics.
(ROOT (NP (NP (NP (NNP Ion) (NNP channels) (NNP facilitate)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-))) (NP (NP (DT the) (NN diffusion)) (PP (IN of) (NP (NP (NNS ions)) (PP (IN across) (NP (DT a) (NN membrane)))))) (. .)))