Systems of biochemical reactions from the point of view of a semigrand partition function.
Semigrand partition functions contain all the thermodynamic information on reaction systems. When they are written for systems at specified pH, they yield the transformed Gibbs energy G' of the system and the thermodynamic properties that can be calculated from G'. When they are written for systems at specified pH and specified concentrations of coenzymes, they yield the further transformed Gibbs energy G" and properties that can be calculated from G". This is illustrated by considering: (1) a reactant that is a weak monoprotic acid at a specified pH; (2) a reaction between two pseudoisomer groups at a specified pH; and (3) the first five reactions of glycolysis. Equilibrium compositions in glycolysis are calculated at pH 7 and different steady-state concentrations of ATP and ADP.
Alberty
R A
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Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. alberty@mit.edu
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D003067:Coenzymes / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006019:Glycolysis / Q000187:drug effects*; D006801:Humans; D008956:Models, Chemical; D009097:Multienzyme Complexes / Q000737:chemistry*; D013816:Thermodynamics
D003067:Coenzymes; D009097:Multienzyme Complexes; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate