( ( The ( charge-transfer reaction ) ) ( ( can ( be ( ( considered ( a ( circuit element ) ) ) ( because ( it ( requires ( ( ( a ( certain amount ) ) ( of overpotential ) ) ( to ( force ( through ( a current ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ charge-transfer) (NN reaction)) (VP (MD can) (VP (VB be) (VP (VBN considered) (NP (DT a) (NN circuit) (NN element)) (SBAR (IN because) (S (NP (PRP it)) (VP (VBZ requires) (S (NP (NP (DT a) (JJ certain) (NN amount)) (PP (IN of) (NP (NN overpotential)))) (VP (TO to) (VP (VB force) (PP (IN through) (NP (DT a) (JJ current)))))))))))) (. .)))
The charge-transfer reaction can be considered a circuit element because it requires a certain amount of overpotential to force through a current.
(ROOT (S (NP (NP (DT The) (NN difference)) (PP (IN between) (NP (NP (DT the) (JJ theoretical) (JJ half-reaction) (NN reduction) (NN potential)) (CC and) (NP (NP (DT the) (JJ actual) (NN voltage)) (VP (VBN required)))))) (VP (VBZ is) (VP (VBN called) (S (ADJP (JJ overpotential))))) (. .)))