Table 1.
Henry’s law constants (Pa m3 mol−1) for conversion of Rubisco kinetic characteristics among gas- and liquid-phase equivalent values (Eqs 8–10)
| Gas | Medium | Temperature (ºC) | |||
|---|---|---|---|---|---|
| 15 | 25 | 35 | 45 | ||
| CO2 | Pure water | 2186 | 2982 | 3867 | 4777 |
| CO2 | Chloroplast | 2230 | 3041 | 3944 | 4873 |
| O2 | Pure water | 67 510 | 82 080 | 97 430 | 113 870 |
| O2 | Chloroplast | 69 260 | 83 950 | 99 370 | 115 840 |
Henry’s law constant (Hpc) is the gas–liquid phase equilibrium partition coefficient and is given as the ratio of the gas partial pressure (Pa) and corresponding liquid-phase concentration (mol m−3, Eq. 3). Because the gas solubility depends on the presence of other solutes (salting-out effect), Hpc typically increases with increasing solute concentration. Equation 4 was used to estimate values of Hpc at different temperatures for pure water, and Eq. 5 for chloroplastic water. In the latter calculation, the dominant solute was assumed to be KCl and the solute concentration was taken as 0.11M. Derivation of Eqs 4 and 5 with supporting references and review of chloroplast solute concentrations is provided in the Methods.