Energy Thermodynamics
Energy Calculations

The reaction from ethanol to carbon dioxide and water is a complex one that proceeds in three steps. Below, the Gibbs Free Energy of Formation for each step is shown with ΔGf values given in the CRC.

Complete Reaction: C2H6O(Ethanol)→C2H4O(Acetaldehyde)→C2H4O2(acetic Acid) →Acetyl-CoA→3H2O+2CO2.

ΔGf = Σ ΔGfp - ΔGfo

Step One: Ethanol: -174.8 kJ/mol
Ethanal(Acetaldehyde): -127.6 kJ/mol
ΔGf1 = -127.6 + 174.8 = 47.2 kJ/mol(Endergonic)
ΣΔGf = 47.2 kJ/mol (Endergonic)

Step Two: Ethanal: -127.6 kJ/mol
Acetic Acid: -389.9 kJ/mol
ΔGf2 = -389.9 + 127.6 = -262.3 kJ/mol (Exergonic)
ΣΔGf = -215.1 kJ/mol (Exergonic)

Step Four: (Because the Gibbs energy is a state function, we can skip the Acetyl-CoA (step 3), for which themodynamic values are not known).
Acetic Acid: -389.9 kJ/mol
3H2O+2CO2: -1500.1 kJ/mol
ΔGf4 = -1500 + 389.6 = -1110.5 kJ/mol (Exergonic)
ΣΔGf = -1325.3 kJ/mol (Exergonic)
[edit] Discussion of calculations

If the catabolysis of alcohol goes all the way to completion, then, we have a very exothermic event yielding some 1325 kJ/mol of energy. If the reaction stops partway through the metabolic pathways, which happens because acetic acid is excreted in the urine after drinking, then not nearly as much energy can be derived from alcohol, indeed, only 215.1 kJ/mol. At the very least, the theoretical limits on energy yield are determined to be 215.1 kJ/mol to 1325.3 kJ/mol. It is also important to note that step 1 on this reaction is endothermic, requiring 47.2 kJ/mol of alcohol, or about 3 molecules of ATP (adenosine triphosphate) per molecule of ethanol.

Моля някой да поясни, че аз нещо се загубих в превода

Защитете бактериите- те са единствената култура в някои хора.