Battley Edwin H
Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794-5245, USA.
J Theor Biol. 2006 Jul 7;241(1):142-51. doi: 10.1016/j.jtbi.2005.11.022. Epub 2006 Jan 30.
Calculations are made of thermal energy exchanges from catabolic reactions in the aqueous state, using thermodynamic properties at 0.001 M, indicated by subscript "(B)". Heats of reaction are calculated as DeltarHB,298.15o'=DeltarXB,298.15o'+DeltarQab,B,298.15o' (1), or as DeltarHB,298.15o'=DeltarGB,298.15o'+TDeltarSB,298.15o' (2), where DeltarXo'B,298.15 and DeltarGo'B,298.15 represent non-thermal, chemical energy converted into thermal energy during a reaction and where DeltarQab,B,298.15o'andTDeltarSB,298.15o' represent the exchange of absorbed thermal energy as reactants become converted into products. Percentages are tabulated of the thermal energy exchanges contributed to DeltarHB,298.15o' by DeltarXB,298.15o' and DeltarQab,B,298.15o', and by DeltarGB,298.15o' and TDeltarSB,298.15o'. Aerobically, for substrates not containing nitrogen, the value of DeltarXB,298.15o' averages 4.21% more negative than that of DeltarGB,298.15o'. For substrates containing nitrogen this average drops to 1.80%. For substances not containing nitrogen, the thermal energy contributed by DeltarQab,B,298.15o' to DeltarHB,298.15o' averages 2.21%, whereas that contributed by TDeltarSB,298.15o' averages -1.95%. The difference is 4.16%, which is close to the average value of 4.21% that DeltarXB,298.15o' is more negative than DeltarGB,298.15o'. This observation indicates that the difference between DeltarXB,298.15o' and DeltarGB,298.15o' is due almost entirely to the manner in which exchanges in absorbed thermal energies are measured or calculated for the reaction systems studied. The same applies to the oxidation of substances containing nitrogen. Here, the thermal energy contributed to DeltarHB,298.15o' by DeltarQab,B,298.15o' averages 5.32%, whereas that contributed by TDeltarSB,298.15o' averages 3.50%. The difference between them is 1.82%, which is close to the average value of 1.80% that DeltarXB,298.15o' is more negative than DeltarGB,298.15o'. Anaerobically, for the processes tested fewer inferences could be drawn. The values of DeltarGB,298.15o' are much more negative than those of DeltarXB,298.15o' in three examples out of five and widely variable, quite the opposite of the data on the aerobic processes. One anaerobic DeltarXB,298.15o' value is positive, indicating that something other than the total free energy change must be driving this particular process.
利用下标“(B)”表示的0.001M时的热力学性质，对水相中分解代谢反应的热能交换进行了计算。反应热计算为ΔrHB,298.15° = ΔrXB,298.15° + ΔrQab,B,298.15° (1)，或ΔrHB,298.15° = ΔrGB,298.15° + TΔrSB,298.15° (2)，其中ΔrX°B,298.15和ΔrG°B,298.15表示反应过程中转化为热能的非热化学能，而ΔrQab,B,298.15°和TΔrSB,298.15°表示反应物转化为产物时吸收热能的交换。列出了由ΔrXB,298.15°和ΔrQab,B,298.15°以及由ΔrGB,298.15°和TΔrSB,298.15°对ΔrHB,298.15°贡献的热能交换百分比。在有氧条件下，对于不含氮的底物，ΔrXB,298.15°的值平均比ΔrGB,298.15°的值负4.21%。对于含氮底物，该平均值降至1.80%。对于不含氮的物质，ΔrQab,B,298.15°对ΔrHB,298.15°贡献的热能平均为2.21%，而TΔrSB,298.15°贡献的热能平均为 -1.95%。差值为4.16%，接近ΔrXB,298.15°比ΔrGB,298.15°更负的平均值4.21%。这一观察结果表明，ΔrXB,298.15°和ΔrGB,298.15°之间的差异几乎完全是由于所研究反应体系中吸收热能交换的测量或计算方式所致。这同样适用于含氮物质的氧化。在此，ΔrQab,B,298.15°对ΔrHB,298.15°贡献的热能平均为5.32%，而TΔrSB,298.15°贡献的热能平均为3.50%。它们之间的差值为1.82%，接近ΔrXB,298.15°比ΔrGB,298.15°更负的平均值1.80%。在厌氧条件下，对于所测试的过程，能够得出的推论较少。在五个例子中有三个例子中，ΔrGB,298.15°的值比ΔrXB,298.15°的值负得多且变化很大，这与有氧过程的数据情况相反。一个厌氧的ΔrXB,298.15°值为正，表明驱动这个特定过程的必定是除总自由能变化之外的其他因素。
