Viscometric study of lysozyme solution with sugar and urea at various temperatures

This paper presents the results of viscosity measurement of three ternary systems i.e. 1- d (−) Glucose + lysozyme + water 2- Maltose + lysozyme + water 3- Urea + lysozyme + water at temperatures (293.15, 303.15, 313.13 and 323.15 K) at various concentrations of glucose, maltose and urea. Change in entropy (ΔH), enthalpy (ΔS) and free energy of activation (ΔG) have also been evaluated for these systems. Value of B-coefficient of d (−) glucose, maltose and urea has also been calculated from viscosity data in aqueous lysozyme solution. Viscosity B-coefficients of glucose and maltose in aqueous lysozyme solution are positive while that of the urea–lysozyme water system it is negative due to the structure breaking effect of urea. The values of entropy of activation are negative due to attainment of transition state for viscous flow, which is accompanied by bond formation and increase in order.