Standard transformed Gibbs energy calculation

The concentration of the reactant is [B] = [BJ + [B2], where [B,] and [BJ are the concentrations of the species at the given pH. The standard transformed Gibbs energy of the reactant when the acid dissociation is at equilibrium can be calculated using... 

The standard transformed heat capacity at constant pressure of a reactant is discussed later in Chapter 10 on calorimetry. The calculation of A H ° using equation 4.5-3 looks simple, but note that the standard transformed Gibbs energies of formation of all of the species are involved in the calculation. These equations were applied to the ATP series by Alberty and Goldberg (1992). 

CALCULATION OF STANDARD TRANSFORMED GIBBS ENERGIES OF SPECIES FROM EXPERIMENTAL MEASUREMENTS OF APPARENT EQUILIBRIUM CONSTANTS... 

Calculation of Standard Transformed Gibbs Energies of Species... 

When the reactant of interest consists of two species with different numbers of hydrogen atoms, the pK of the weak acid is needed to calculate ArC °(/ = 0) of the two species, and the calculation is more complicated. The standard transformed Gibbs energy of formation of a pseudoisomer group containing two species is given by... 

In order to calculate the standard transformed Gibbs energies of formation of the four oxygenated forms of hemoglobin, we need the value of AfG° for molecular oxygen in aqueous solution at 21.5°C. The NBS Table (1992) indicates that ArG0(O2(ao)) = 16.1 kJ mol-1 at 21.5°C. The value of ArG 0(T(O2)) is calculated using... 

The values of the standard transformed Gibbs energies of formation of the five forms of hemoglobin at specified T, P, and buffer can be used to calculate the equilibrium constants for other reactions that can be written between these forms, such as T + 402 = T(02)4. But it is also of interest to consider the tetramer of hemoglobin as an entity at a specified pressure of molecular oxygen, just as ATP is considered as an entity at a specified pH. This is discussed in the next section. 

The values of A, G ° for the catalytic site, succinate, and site-succinate calculated in this way are shown in Table 7.5. Similar calculations have been made for D-tartrate, L-tartrate, and meso-tartrate using data from Table 7.4. Since the ArG° values for these three reactants are not known, the convention has been adopted that they are equal to zero. Table 7.5 shows that standard transformed Gibbs energies of formation at specified pH values can be calculated for an unoccupied binding site and the binding site occupied by a ligand. 

The change in binding of hydrogen ions in a biochemical reaction can be calculated from the derivative of the standard transformed Gibbs energy of... 

Calculation of the functions of pH and ionic strength for the standard transformed Gibbs energy of formation of reactants. 

This program can be used to calculate standard transformed Gibbs energies of reaction or standard transformed enthalpies of reaction in kJ mol"1. To calculate the changes in standard transformed enthalpy, an h is appended to the name of the reactant. 

Calculate the functions that yield the standard transformed Gibbs energies of the reactants in the reaction atp + h2o = adp + pi at 313.15 K. 

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