where \(r_{R}\) is the RuBisCO turnover rate; \(n_{ef}\) is the number of electrons needed to reduce \(\text{CO}_{2}\) to a fuel molecule; \(n_{R}\) is the number of RuBisCO molecules per cell; and \(n_{Cf}\) is the number of \(\text{CO}_{2}\) molecules required to synthesize one fuel molecule. Thus, the \(\text{H}_{2}\)demand rate per cell,