( For ( ( a ( redox reaction ) ) ( that ( ( takes place ) ( in ( ( ( a cell ) , ) ( the ( potential difference ) ) ) ) ) ) ) )
(ROOT (PP (IN For) (NP (NP (DT a) (NN redox) (NN reaction)) (SBAR (WHNP (WDT that)) (S (VP (VBZ takes) (NP (NN place)) (PP (IN in) (NP (NP (DT a) (NN cell)) (, ,) (NP (DT the) (JJ potential) (NN difference))))))))))
For a redox reaction that takes place in a cell, the potential difference
(ROOT (S (NP (JJ Biochemical) (NNS reactions)) (VP (VBP take) (NP (NP (NN place)) (PP (IN inside) (NP (NP (DT the) (NNS organisms) (POS ')) (NNS cells))))) (. .)))