Gibbs free energy of hydrolysis of energy-rich compounds involved in Substrate Level Phosphorylation (SLP)

Range Table - link
Organism Various
Reference Thauer RK, Jungermann K, Decker K. Energy conservation in chemotrophic anaerobic bacteria.Bacteriol Rev. 1977 Mar41(1):100-80. p.108 table 4PubMed ID860983
Primary Source See pointers to refs in right of table
Comments P.108 left column bottom paragraph: ""Energy-rich" compounds are characterized by their free energy of hydrolysis ("group transfer potential") (ΔGO'), which lies in the range of -5 to -15 kcal/mol (-20.9 to -62.8 kJ/mol) and by the fact that they exist in an enzymatic equilibrium with the ATP system. These "energy-rich" compounds are acid anhydrides or thioesters (Table 4), i.e., derivatives of carboxylic acids which represent the highest oxidation level of the carbon atom in organic compounds. Acetals, thioacetals, ethers, and thioethers are not energy rich. Therefore "energy-rich" compounds can only be formed by the dehydrogenation of carbonyl groups or by lysis of carboxyl functions that are on the highest oxidation level already. Therefore, SLP can only be linked to the electron-donating part of catabolic redox processes or to the lytic part of catabolic nonredox processes." Substrate-level phosphorylation is a type of chemical reaction that results in the formation and creation of adenosine triphosphate (ATP) by the direct transfer and donation of a phosphate group to adenosine diphosphate (ADP) from a reactive intermediate. In cells, it occurs primarily and firstly in the cytoplasm (in glycolysis) under both aerobic and anaerobic conditions.
Entered by Uri M
ID 104429