Thermodynamics of the conversion of aqueous glucose to fructose
| Autor: | Yadu D. Tewari, Robert N. Goldberg |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Isothermal microcalorimetry
Standard enthalpy of reaction Aqueous solution Chemistry Enthalpy Biophysics Thermodynamics Bioengineering Fructose General Medicine Calorimetry Applied Microbiology and Biotechnology Biochemistry Heat capacity Enzyme catalysis Gibbs free energy chemistry.chemical_compound symbols.namesake symbols Physical and Theoretical Chemistry Molecular Biology Equilibrium constant Biotechnology |
| Zdroj: | Journal of Solution Chemistry. 13:523-547 |
| ISSN: | 1572-8927 0095-9782 |
| DOI: | 10.1007/bf00647222 |
| Popis: | The thermodynamics of the conversion of aqueous glucose to fructose has been investigated using both heat conduction microcalorimetry and high pressure liquid chromatography (HPLC). The reaction was carried out in both aqueous TRIS/HCl buffer and in aqueous phosphate buffer in the pH range 7 to 8 using the enzyme glucose isomerase and the cofactors CoCl2 and MgSO4. The temperature range over which this reaction was investigated was 298.15 to 358.15 K (25–85°C). We have found that the enthalpy of reaction is independent of pH over the range 7 to 8. A combined analysis of both the HPLC and microcalorimetric data leads to the following results at 25°C: ΔGo=349±53 J-mol−1, ΔHo=2780±200 J-mol−1, and ΔC p o =76±30 J-mol−1-K−1. The stated uncertainties are based upon an analysis of both the random and systematic errors inherent in the measurements. The temperature dependence of the equilibrium constant K for the process is expressed as $$RinK = - \frac{{349}}{{298.15}} + 2780(\frac{1}{{298.15}} - \frac{1}{T}) + 76(\frac{{298.15}}{T} - 1 + \ln \frac{T}{{298.15}})$$ Comparisons are made with literature data. |
| Databáze: | OpenAIRE |
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