Additional Capabilities of BioEqCalcSeveral additional classes of problems that BioEqCalc can solve are described in this section. As, in the previous sections, we continue to use the example of the ATP hydrolysis reaction although essentially any other biochemical reaction could have been used. Example 5.
This example uses a (hypothetical) measured value of the apparent equilibrium constant and the function
All of the parameters used by The calculated value K = 0.2946 for the chemical reference reaction (3) is identical to the value used initially (see Example 3).
Example 6.In this example, the aim is to calculate the standard molar transformed enthalpy of reaction . The module uses the relationship:
Here, R is the gas constant (8.31451 J ) and P is pressure. This calculation is done with the function
The calculated value of is in excellent agreement with the value obtained previously by Alberty and Goldberg [13].
Example 7.This example demonstrates the calculation of the change in binding of the ion, , accompanying the biochemical reaction (3) at , , , and . The function uses the relationship:
Note that temperature, ionic strength, and the values of are held constant in calculating the derivative. This calculation uses the function
In this case, the index of is 3 and . The index of is 11 and . The result was obtained by Alberty and Goldberg [13].
Example 8.Similarly, we now wish to calculate the change in binding at , , , and . This problem is analogous to Example 7 except that the roles of and are reversed. The result was obtained by Alberty and Goldberg [13].
Example 9.We now wish to calculate the calorimetric enthalpy . This calculation uses the relationship [14] where is the standard molar enthalpy of ionization of the buffer at the specified ionic strength and temperature. is obtained by first using the function
Example 10.This example demonstrates the calculation of the standard molar enthalpy of reaction for the chemical reference reaction (3). This calculation uses the function
Example 11.This example demonstrates application to a system consisting of the following three biochemical reactions:
Here, G6P is glucose 6-phosphate and AMP is adenosine -monophosphate. The system is described by 20 reactions and 29 species. Although more complex than the previous examples, the principles are the same.
Example 12.It is also possible to perform equilibrium calculations on systems of biochemical reactions without any knowledge of the ionic equilibria. For example, if one knows the values of for the biochemical reactions (7), (8), and (9), one can use
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