Macromolecule speciation in chemical equilibrium
The equilibrium of the conformation reactions of macromolecules can be simplified to the reactions of their selected electro-neutral forms of the selected conformation, because of the law of detailed balance.
The assumptions of this calculation are:
| xm | the probability of macromolecule(of the selected conformation) | 
| fi = (xi/xm) | the probalitivy of selected independent subunits forms (of the macromolecule in the selected conformation) | 
| xs = xm· Π fi = xm· Π (xi/xm) | the probability of the selected form of macromolecule (composed from selected subunits in the selected conformation) | 
| us = us° + R·T·ln(xm) + ∑ (ui - R·T·ln(xm)) | final equation of the equilibrium of electro-chemical potential | 
Notations
| nT | total amount of substances in the solution | 
| nm | total amount of the macromolecule (of the selected conformation) in the solution | 
| ns | amount of the specific form of the macromolecule (of the selected conformation) in the solution | 
| ni | amount of the specific form of the i-th macromolecule(of the selected conformation)'s subunit in the solution | 
| xm = nm / nT | mole fraction of macromolecule (of the selected conformation) | 
| xs = ns / nT | mole fraction of the selected form of the whole macromolecule (composed from selected subunits in the selected conformation) | 
| xi = ni / nT | mole fraction of i-th macromolecule(of the selected conformation)'s subunit form | 
| us° | base chemical potential of the selected form of the macromolecule (composed from selected subunits in the selected conformation) | 
| us = us° + R·T·ln(xs) | chemical potential of the selected form of the macromolecule (composed from selected subunits in the selected conformation) | 
| ui° = 0 | base chemical potential of the specific form of the i-th macromolecule(of the selected conformation)'s subunit in the solution | 
| ui = R·T·ln(xi) | chemical potential of the specific form of the i-th macromolecule(of the selected conformation)'s subunit in the solution | 
For example: If the macromolecule M has four identical independent subunits and each subunit can occur in two form F1 and F2, then the probability of macromolecule form S composed only from four subunits in form F1 is P(S)=P(M)*P(F1)^4.
| Name | Description | 
|---|---|
| Substance model to translate data into substance properties | 
2013-2015 by Marek Matejak, Charles University, Prague, Czech Republic