( ( In ( most organisms ) ) ( , ( ( this ( protonmotive force ) ) ( ( is ( generated ( by ( ( redox reactions ) ( that ( ( are either ) ( ( ( ( photochemically driven ) ( -LRB- ( ( ( e.g. , ) ( photosynthetic ( reaction centers ) ) ) -RRB- ) ) ) or ) ( ( intrinsically spontaneous ) ( -LRB- ( ( ( ( e.g. , ) ( oxidative phosphorylation ) ) ( in mitochondria ) ) -RRB- ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (JJS most) (NNS organisms))) (, ,) (NP (DT this) (JJ protonmotive) (NN force)) (VP (VBZ is) (VP (VBN generated) (PP (IN by) (NP (NP (NN redox) (NNS reactions)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (DT either) (ADJP (ADJP (ADJP (RB photochemically) (JJ driven)) (PRN (-LRB- -LRB-) (NP (NP (NNP e.g.)) (, ,) (NP (JJ photosynthetic) (NN reaction) (NNS centers))) (-RRB- -RRB-))) (CC or) (ADJP (ADJP (RB intrinsically) (JJ spontaneous)) (PRN (-LRB- -LRB-) (NP (NP (NNP e.g.)) (, ,) (NP (JJ oxidative) (NN phosphorylation))) (PP (IN in) (NP (NN mitochondria))) (-RRB- -RRB-))))))))))) (. .)))
In most organisms, this protonmotive force is generated by redox reactions that are either photochemically driven (e.g., photosynthetic reaction centers) or intrinsically spontaneous (e.g., oxidative phosphorylation in mitochondria).
(ROOT (S (NP (DT A) (JJ voltaic) (NN cell)) (VP (VBZ generates) (NP (DT an) (JJ electric) (NN current)) (PP (IN through) (NP (NP (DT a) (NN reaction)) (VP (VBN known) (PP (IN as) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (JJ spontaneous) (NN redox))))))) (. .)))