ライフサイエンスコーパス: electron transfer

1 n energy of 0.7 +/- 0.1 eV for excited-state electron transfer.

2 atalytic ammonia synthesis by proton-coupled electron transfer.

3 novel function of protonation resulting from electron transfer.

4 cal vacancies, and lowered the resistance to electron transfer.

5 ing glutamate (E205) residue in intersubunit electron transfer.

6 uch as enzymatic catalysis, respiration, and electron transfer.

7 egulates photosynthetic light harvesting and electron transfer.

8 e a Ni(II) superoxo complex via ligand-based electron transfer.

9 rs within protein active sites to facilitate electron transfer.

10 ectron donors that facilitate proton-coupled electron transfer.

11 reduced complexes undergo unproductive back electron transfer.

12 matic O(2) reduction involves proton-coupled electron transfers.

13 between chromophoric units such as energy or electron transfers.

14 We observe ballistic electron transfer (~30 fs) along a reaction coordinate c

15 us solution improves the ionic migration and electron transfer across the film and promotes the forma

16 x probes can be addressed by electrochemical electron transfer across the rim of nanospheres, and the

17 ntribution in the postulation of this single-electron transfer agent (SET) as a new green catalyst wi

18 re produced in organisms and are utilized as electron transfer agents, pigments and in defence mechan

19 lonate pathway for maintaining mitochondrial electron transfer and biosynthetic activity in cancer ce

20 , and diversification, evolved to facilitate electron transfer and catalysis at a very early stage in

21 hotoredox-catalyzed reactions, in which back-electron transfer and chain propagation are competing pa

22 could boost efficiency of energy storage by electron transfer and identifies size-mismatch as an imp

23 The enhanced electron transfer and increased electrochemical surface

24 CDs-fed cells show accelerated extracellular electron transfer and metabolic rate, with increased int

25 emble upon ATP binding to BchL to coordinate electron transfer and protochlorophyllide reduction.

26 The mechanism of coupling between ion or electron transfer and proton translocation in this large

27 ndicate a huge kinetic advantage for aqueous electron transfer and redox catalysis that takes place p

28 ases, the ion adsorption on the PTFE hinders electron transfer and results in the suppression of the

29 The mechanisms of extracellular electron transfer and the microbial taxa associated with

30 howed, on the one hand, a negative effect on electron transfer and, on the other hand, improved hydro

31 luence on the kinetics and thermodynamics of electron transfer, and frequently defines the success or

32 ively modifies the N(2) absorption, improves electron transfer, and offers extra redox couples for NR

33 coinciding with charge separation, secondary electron transfer, and stimulated emission decay.

34 processes are referred to as proton-coupled electron transfer, and they underpin a wide variety of b

35 odes of HF4TCNQ(-), formed by proton-coupled electron transfer, are identified, and we demonstrate th

36 .e., His, Asp, and Glu, were able to mediate electron transfer at physiological pH.

37 s demonstrates a new WGS pathway featured by electron transfer at the active site from Fe(3+) -O...Ir

38 Polarization change induced by directional electron transfer attracts considerable attention owing

39 Mechanistic studies indicate a single-electron transfer-based pathway.

40 also limited its diffusion, which resembled electron-transfer behavior of quinone- and hydroquinone-

41 olves a reversible stimulated intramolecular electron transfer between a redox-active ligand and redo

42 action proceeds by violet-light photoinduced electron transfer between an N-alkoxyphthalimide-based o

43 In the future, such targeted electron transfer between host {Mo(132)} and a transitio

44 PTFE, which further confirms the presence of electron transfer between liquid and solid, simply becau

45 In vivo, biofilm eDNA can also support rapid electron transfer between redox active intercalators.

46 n couples, identify and quantify the rate of electron transfer between the reduced and oxidized speci

47 Photoinduced electron transfer can produce radical pairs having two q

48 The electron transfer capacity of local configurations is us

49 cules have been shown to behave as competent electron-transfer catalysts in photoredox reactions, the

50 importance of protein motion in inter-copper electron transfer catalyzed by CuNiRs.

51 ced processes in intermediates of sequential electron transfer chains.

52 s, (ii) the more favorable driving force for electron transfer, characterized by more positive E(1/2)

53 catecholamine redox reactions at LSGE as the electron transfer-chemical reaction-electron transfer me

54 ization of nanoparticles as 'nano-tools' for electron transfer, chemotaxis, and storage units, and (i

55 he elimination or mitigation of photoinduced electron transfer could substantially improve the emissi

56 ntacene dimers exhibits a selectively higher electron-transfer coupling with near-zero hole-transfer

57 ed substrates via reductive concerted proton-electron transfer (CPET) must overcome competing, often

58 These concerted proton-electron-transfer (CPET) reactions are implicated in num

59 ry example is the binuclear Cu(A) center, an electron transfer cupredoxin domain of photosynthetic an

60 rucaria bilirubin oxidase (MvBOD) for direct electron transfer (DET) in the dioxygen reduction reacti

61 abolites, where the employment of the direct electron transfer (DET) principle is expected.

62 d in the context of the often-claimed direct electron transfer (DET) to glucose oxidase at carbon nan

63 GCE|BOx) was used as the cathode with direct electron transfer (DET).

64 of both metal centers, a direct read-out of electron transfer, determines the presence of the substr

65 show that such fiber-assisted activated ion-electron transfer dissociation (AI-ETD) and IR multiphot

66 Activated ion electron transfer dissociation (AI-ETD) uses concurrent

67 tly developed technique called activated ion electron transfer dissociation (AI-ETD).

68 first application of activated-ion negative electron transfer dissociation (AI-NETD) to nucleic acid

69 The instrument was already fitted with electron transfer dissociation (ETD) between the quadrup

70 Negative electron transfer dissociation (NETD) has proven valuabl

71 in addition to the standard SPS workflow, an electron-transfer dissociation (ETD) MS2 was performed a

72 hange mass spectrometry (HDX-MS) followed by electron-transfer dissociation (ETD), chemical cross-lin

73 molecular HAA reactions in solution that are electron transfer-driven and highly exergonic have the l

74 The electron transfer dynamics from photoexcited QDs to the

75 whether anammox bacteria have extracellular electron transfer (EET) capability with transfer of elec

76 Extracellular electron transfer (EET) in microorganisms is prevalent i

77 Microbial extracellular electron transfer (EET) stimulates a plethora of intelle

78 How these shuttles catalyze extracellular electron transfer (EET) within biofilms without being lo

79 ducing bacterium and model for extracellular electron transfer (EET), a respiratory mechanism in whic

80 Thus, Bf-ETFs may optimize electron transfer efficiency by enabling direct flavin-f

81 n cascades, ligand binding and dissociation, electron transfer, enzymatic reactions, and protein un-

82 by the oligomeric architecture found in many electron transfer enzymes.

83 ighlight the alterations in the photoinduced electron transfer (ET) and hydrogen atom transfer (HAT)

84 ric architectures are found in several other electron transfer (ET) complexes, but how this architect

85 ve explored the kinetic effect of increasing electron transfer (ET) distance in a biomimetic, proton-

86 adenosyl-l-methionine (SAM) enzymes involves electron transfer (ET) from [4Fe-4S](+) to SAM, generati

87 spectroscopy, elucidate the critical role of electron transfer (ET) from CdS NRs to MmOGOR.

88 nderstanding of how nitrogenase orchestrates electron transfer (ET) from the Fe-protein to the cataly

89 Rate constants for bimolecular electron transfer (ET) increased with driving force, -De

90 Rapid and directed electron transfer (ET) is essential for biological proce

91 ling with the Cu(II) sites reflecting facile electron transfer (ET) pathways, which may be protective

92 a stepwise one proton transfer (PT) and two electron transfer (ET) processes.

93 A variety of electron transfer (ET) reactions in biological systems o

94 of proline spacers compared to the analogous electron transfer (ET) systems.

95 The fundamental biological process of electron transfer (ET) takes place across proteins with

96 ctures that promote facile PT concerted with electron transfer (ET), known as the Volmer mechanism.

97 organization energy, lambda, for interfacial electron transfer, ET, from a conductive electrode to re

98 tate rapid intraflavin and trans FMN-to-heme electron transfers (ETs).

99 of oxidizing or reducing reagents as well as electron transfer events by electric current.

100 Solution electron-transfer experiments and cyclic voltammetry sho

101 rrier, and the other to the higher-E degrees electron transfer FAD (ET-FAD).

102 peripheral electron flow from photosynthetic electron transfer, findings that reveal detailed insight

103 beta-FAD of the electron transfer flavoprotein (EtfAB) from the anaerobi

104 xyl group the O(2) reduction proceeds via an electron transfer followed by proton transfer to the Fe(

105 ed predominantly (56)Fe(II), indicating that electron transfer from adsorbed (57)Fe to (56)Fe of the

106 arget binding-induced changes in the rate of electron transfer from an electrode-bound receptor.

107 n act as electron shuttles thus facilitating electron transfer from Fe(III)-reducing bacteria (FeRB)

108 2)PO(4)} and furthermore showed photoinduced electron transfer from M to Mo.

109 s from the blockage of the optically excited electron transfer from MoSe(2) to WS(2).

110 Further electron transfer from one-electron reduced, Rieske-type

111 ce of oxygen vacancies, leading to efficient electron transfer from perovskite to TiO(2) .

112 dicate that PFOS degradation is initiated by electron transfer from sulfonate to iron.

113 surfaces, which are supplied with high-flux electron transfer from the buried carbon interlayer.

114 Back-electron transfer from the DCA radical anion followed by

115 y used in enzymatic fuel cells, where direct electron transfer from the electrode to the enzymatic ac

116 sitized Eu(III) luminescence by photoinduced electron transfer from the excited light-harvesting ante

117 adsorption mechanism involving outer-sphere electron transfer from the framework to form superoxide

118 ium facilitates rare, thermally allowed full electron transfer from the Green Box to fullerene in the

119 tivated heteroarene but also accelerates the electron transfer from the nitrogen radical intermediate

120 e-separated state via ultrafast photoinduced electron transfer from the PE(4) segment to NDI when exc

121 excited state (LES) is followed by concerted electron transfer from the phenol to the anthracene and

122 eneral, the promotion is achieved through an electron transfer from the S to neighboring metal-atom s

123 rted PCET mechanism involving intramolecular electron transfer from tyrosine to Ru(bpy)(3)(3+) and pr

124 that at the defect-free Au/TiO(2) interface electrons transfer from Ti(3+) species into Au nanoparti

125 high-throughput phenotypic AST by measuring electrons transferred from the interiors of microbial ce

126 Moreover, this heterojunction impedes electrons transferring from BiCuSeO to Cu(2) Se, obstruc

127 ch moves the E and F-helices and switches an electron transfer gate formed by LysF7, GlnE7, and water

128 e of microorganisms performing extracellular electron transfer has been established in many environme

129 Photoinduced single electron transfer has been initiated by utilizing the vi

130 and performed quasi-reversible heterogeneous electron transfer (HET).

131 pike proteins using signature ions-triggered electron-transfer/higher-energy collision dissociation (

132 d O-glycans were unambiguously identified by electron-transfer/higher-energy collision dissociation t

133 atography (LC)-MS, and then fragmented using electron-transfer/higher-energy collisional dissociation

134 However, its slow intramolecular electron transfer (IET) rate from the FAD to the heme, l

135 TOF is achieved through rapid intramolecular electron transfer (IET) to the native intermediate (NI),

136 tetrabromopyrene (TBP), and the photoinduced electron transfer in a TBPCExBox(4+) supramolecular dyad

137 tron uptake is emerging as a key process for electron transfer in anaerobic microbial communities, bo

138 Carbon nanodots (CNDs) undergo electron transfer in different scenarios.

139 As paradigms for proton-coupled electron transfer in enzymes and benchmarks for a fully

140 We propose that such sequential electron transfer in oligomeric enzymes serves as a regu

141 n-EPR is broadly applicable for the study of electron transfer in other redox enzymes and paves the w

142 In contrast, interfacial electron transfer in PFE is fast, lifting the electron-t

143 associated with electron and proton-coupled electron transfer in the electric double layer.

144 Electron transfer induced proton transfer across a H-bon

145 Photoinduced electron transfer, initiated using 365 nm light-emitting

146 Resonant electron transfer into TPP molecules occurs at <+1 V in

147 Although electron transfer involves metal-localized orbitals, inv

148 The data provide direct evidence of electron transfer involving the lowest-energy ligand-fie

149 Long-range electron transfer is coupled to proton transfer in a wid

150 can be coupled with electron transfer; this electron transfer is in general non-integer and unknown

151 Hence, electron transfer is likely the dominating effect for th

152 t potential energy surfaces, indicating that electron transfer is likely to be slow.

153 onsive H-bond dimers based on proton-coupled electron transfer is proposed that capitalizes on the im

154 On the contrary, electron transfer is suppressed with excitation at longe

155 ate electronic coupling, likely photoinduced electron transfer, is responsible for the quenching effe

156 d, and there is no information regarding the electron transfer kinetics and thermodynamics of redox-a

157 Here, we report the interfacial electron transfer kinetics for molecules positioned at v

158 cal impedance spectroscopy (EIS) showed fast electron transfer kinetics of ZnO-rGO/ITO electrode.

159 vious claims that binding-induced changes in electron-transfer kinetics drive signaling in this class

160 (2) activation goes through a proton-coupled electron-transfer-like mechanism.

161 ically limited by diffusional intermolecular electron transfer, masking the KIE.

162 ues is attributed to the fast and unhindered electron transfer mechanism of ZnO-rGO matrix having low

163 of binding O(2) through such an outer-sphere electron transfer mechanism represents a promising and u

164 ility to reduce acrylamides through a single electron transfer mechanism.

165 imately - 3 V versus SCE by a proton-coupled electron transfer mechanism.

166 E as the electron transfer-chemical reaction-electron transfer mechanism.

167 spectroscopy, suggests that a proton-coupled electron-transfer mechanism is operational as part of a

168 f alcohol O-H bonds through a proton-coupled electron-transfer mechanism.

169 ls of bioelectrocatalytic systems, including electron transfer mechanisms, electrode materials, and r

170 dehalogenations and cyclizations via single electron transfer mechanisms.

171 tal insights into adiabatic and nonadiabatic electron transfer mechanisms.

172 lytic transformations via previously unknown electron transfer mechanisms.

173 Our results are helpful to explain the electron-transfer mechanisms in particulate NOM.

174 An efficient Pd/ETM (ETM = electron transfer mediator)-cocatalyzed stereoselective

175 e across oxidoreductase enzymes that rely on electron transfer mediators.

176 of organismal functioning, as the link among electron transfer, metabolism, energy conservation, and

177 ts to achieve multiple-site concerted proton-electron transfer (MS-CPET) activation of a C-H bond in

178 otoredox-mediated multisite concerted proton-electron transfer (MS-PCET) and nickel catalysis.

179 Partial restoration indicates dual-channel electron transfer of NfoR via Cu(II) and FMN.

180 include i) being the first to report direct electron transfer of oxidoreductase enzymes enabled by s

181 urface hydrophobicity, charge transport, and electron transfer) of organic self-assembled monolayers

182 In redox metalloenzymes, the process of electron transfer often involves the concerted movement

183 uench photogenerated excitons via energy and electron transfer on the femto-nanosecond time scale, th

184 7)Fe(II), suggesting a longer time scale for electron transfer on the Gt surface.

185 Evolution favored productive electron transfer only via the D1 branch, with the preci

186 However, laccase can perform a direct electron transfer only when it is in the preferred orien

187 ace as the rate-determining step rather than electron transfer or ion diffusion.

188 provide information on the degree of coupled electron transfer or the potential change at the point o

189 lipid-mediated NADPH-binding pocket and the electron transfer path.

190 ion of a second chromophore, heme, yields an electron transfer pathway in both micelles and fibers th

191 upport the validity of the energy as well as electron transfer pathways in the visible light-mediated

192 reactions through generation of alternative electron transfer pathways, while it reduces photochemic

193 Proton-coupled electron transfer (PCET) from tyrosine produces a neutra

194 Photoredox catalysis using proton-coupled electron transfer (PCET) has emerged as a powerful metho

195 exploiting the base-assisted proton-coupled electron transfer (PCET) pathway.

196 ite at copper(II) following a proton-coupled electron transfer (PCET) pathway.

197 the flavin induces a forward proton-coupled electron transfer (PCET) process that leads to the forma

198 Recently the proton-coupled electron transfer (PCET) rate constants for a series of

199 Interfacial proton-coupled electron transfer (PCET) reactions are central to the op

200 -H bonds are shown to undergo proton-coupled electron transfer (PCET) to azobenzene to generate diphe

201 ET) distance in a biomimetic, proton-coupled electron-transfer (PCET) system.

202 the strategies of blocking the photo-induced electron transfer (PET) and CN isomerisation mechanisms.

203 gation process proceeds through photoinduced electron transfer (PET) between Trp and the pyridinium s

204 anine dyes, herein we show that photoinduced electron transfer (PeT) from a thiolate to Cy in their t

205 Photoinduced electron transfer (PET) is a phenomenon whereby the abso

206 f the pyridazinone scaffold and photoinduced electron transfer (PET) mechanism, we designed a smart n

207 one oxime radical cations using photoinduced electron transfer (PET) with DCA as the photosensitizer.

208 of an electronically decoupled, photoinduced electron transfer (PET)-capable subunit in meso-position

209 It is demonstrated that electron transfer plays the dominant role during CE betw

210 for P. falciparum 18S rDNA by photo-induced electron transfer polymerase chain reaction.

211 us glucose monitoring system based on direct electron transfer principle.

212 across 2 cm distances and shed light on the electron transfer process in natural anoxic environments

213 The electron transfer process in the AbCntA-E205A mutant is

214 all chemically reversible two-proton-coupled electron-transfer process (E2PT) takes place upon electr

215 -N coupling methods are (1) a proton-coupled electron-transfer process promoted by a phosphate base,

216 ophorbide-a) by ultrasound participate in an electron-transfer process with the surrounding biologica

217 rption spectroscopy, we were able to observe electron transfer processes associated with radical form

218 nols participate in both proton transfer and electron transfer processes in nature either in distinct

219 ceptor systems that model the intermolecular electron transfer processes of Nature's photosynthetic c

220 c (Cyt c) has evolved to become an important electron-transfer protein in humans.

221 ic metabolism through specific extracellular electron transfer proteins and was effective for a varie

222 The data reveal small intrinsic barriers for electron transfer proximate to conductive interfaces, wh

223 In this paper, a quasi-direct electron transfer (quasi-DET) type lactate sensor was de

224 ely correlate with changes in estimated PSII electron transfer rate and CO(2) assimilation.

225 ents showed a significant enhancement in the electron transfer rate of all tested electroactive speci

226 emical tag), leading to the variation of the electron transfer rate of the electrochemical tag.

227 amework that connects charge conductance and electron transfer rate.

228 nd the correlation between the heterogeneous electron-transfer rate constant (10(-3) cm s(-1)) and th

229 (6)-fold, which largely promoted the overall electron-transfer rate during microbial iron(III) minera

230 a working electrode to observe the enhanced electron-transfer rate in the EAST.

231 lectron transfer in PFE is fast, lifting the electron-transfer rate limitation and manifesting a KIE

232 xperimentally determined exchange couplings, electron transfer rates, and electron transport conducta

233 the cage are useful handles to fine-tune the electron transfer rates, paving the way for the encapsul

234 ctron transport chain and is involved in the electron transfer reaction between cytochrome c1 and c.

235 nal theory simulations suggest that a direct electron transfer reaction was the probable rate-determi

236 This leads to the generation (by the electron transfer reaction, not the laser pulse) of a ne

237 sively out of equilibrium as a result of the electron transfer reaction.

238 s provides an energetic driving force for an electron-transfer reaction(1-4).

239 The purified HoxEFU subcomplex catalyzed electron transfer reactions among NAD(P)H, flavodoxin, a

240 Life on Earth is driven by electron transfer reactions catalyzed by a suite of enzy

241 portance of phenoxy radicals produced by one-electron transfer reactions initiated by chlorine in the

242 zations show that in multiple proton-coupled electron transfer reactions MOF-based redox hopping is n

243 rol the yield and kinetics of the sequential electron transfer reactions that transform light energy

244 s undergo a cascade of sequential energy and electron transfer reactions that ultimately yield charge

245 can enable the dramatic acceleration of some electron transfer reactions, and control it by suppressi

246 Unlike alternative methods used to study electron transfer reactions, the cryoreduction approach

247 substances (PFASs) through potential-driven electron transfer reactions.

248 lants as protein cofactors mediating diverse electron transfer reactions.

249 to stabilize the charge-separation steps of electron-transfer reactions.

250 2 was established as a single electron transfer reagent by treating it with an accepto

251 by serving as Lewis acids for intramolecular electron-transfer, redox-innocent Lewis acids separate t

252 sulfur speciation, corrosion potential, and electron transfer resistance are determined.

253 ody-centered-cubic (BCC) structure and lower electron-transfer resistance, providing higher reactivit

254 ultiple steps associated with proton-coupled electron transfer result in sluggish OER kinetics and ca

255 Herein, ligand-to-substrate single-electron transfer results in one-electron-reduced Fische

256 and reactivity studies are presented for an electron transfer series of copper hydroxide complexes s

257 tion scheme that is sensitive to both single electron transfer (SET) and hydrogen atom transfer (HAT)

258 methylaniline (5) is a poor probe for single electron transfer (SET) because the corresponding radica

259 The process is triggered by a single electron transfer (SET) event involving a photoexcited e

260 k system was developed to investigate single-electron transfer (SET) in the reactions of organomagnes

261 tion and (3) the catalyst undergoes a single electron transfer (SET) process with the alkyl bromide.

262 is capable of facilitating a range of single-electron transfer (SET) processes, including hydrogen at

263 ions of Lewis acids and bases undergo single-electron transfer (SET) processes.

264 istry offers opportunities to promote single-electron transfer (SET) redox-neutral chemistries simila

265 ms that would be capable of mediating single electron transfer (SET) to the C(sp(3))- or C(sp(2))-hyb

266 Subsequent single electron transfer (SET) to this system initiates a rearr

267 yl radical anions and proceeded via a single-electron-transfer (SET) mechanism.

268 ate an initial intramolecular proton-coupled electron-transfer step yielding the E1PT product followe

269 o photoredox catalytic cycles through single-electron transfer steps has become a powerful tool in th

270 n of all of the triads results in sequential electron transfer that generates the identical final cha

271 at CE between two solids is primarily due to electron transfer, the mechanism for CE between liquid a

272 This rate data was described well by electron transfer theory subject to a diffusion-controll

273 ns to the surface, which can be coupled with electron transfer; this electron transfer is in general

274 Control of photoinduced electron transfer through selective excitation of a pai-

275 By integrating electron-transfer through the judicious design of asymme

276 anella oneidensis MR1, proceeds via a single electron transfer to form a pentavalent U(V) intermediat

277 termediate activates alkyl halides by single electron transfer to form alkyl radical intermediates an

278 Overall, O(2) undergoes single electron transfer to form short-lived superoxide, which

279 he formation of N-H bonds via proton-coupled electron transfer to generate a mu-amide product.

280 ndrial activity with glycolysis by balancing electron transfer to mitochondria, thereby supporting gl

281 nstrate how differences in the time scale of electron transfer to Pd clusters translate into hydrogen

282 1+) enzyme absent substrate results in rapid electron transfer to SAM with accompanying homolytic S-C

283 The contribution of photoinduced electron transfer to the overall reduction of the Eu(III

284 akoid membrane to optimise the efficiency of electron transfer to the prevailing light conditions, is

285 states for PhBr could provide a pathway for electron transfer to the surface in the case of the arom

286 rophilicity of the solid affect the ratio of electron transfers to ion transfers.

287 mical-genetic hybrids feature a photoinduced electron transfer triggered RhoVR voltage-sensitive indi

288 c structure theory to explore reactivity and electron transfer using periodic, molecular, and embedde

289 ion-electron hopping" model, suggesting that electron transfer via the immobilized AQDS/AH(2)QDS coup

290 Thus, we postulate that the 2 cm electron transfer was enabled by a combination of AQDS m

291 ggesting that the mechanism of heterogeneous electron transfer was not affected by the electrode pote

292 rthermore, wavelength-dependent photoinduced electron transfer was not observed in either T(4)NDI or

293 This previously unidentified electron transfer was occluded during previous in vivo s

294 d potential resulted in an increased rate of electron transfer, which ultimately increased the measur

295 calculations, we directly infer the coupled electron transfer, which we find to be on the order of 0

296 Actuating electron transfer with O(2) and NO movements averts irre

297 intermediates effectively couple interfacial electron transfer with oxidative C-H/N-H coupling chemis

298 rs, we demonstrate that coupling metal-based electron transfer with secondary coordination sphere eff

299 Ubiquinone 8 (coenzyme Q8 or Q8) mediates electron transfer within the aerobic respiratory chain,

300 easing electrochemical potential for the two electron transfers within the catalytic cycle.