Carbon oxidation goes along with acidification
Biological energy metabolism involves the oxidation of carbon from organic compounds. Although oxidation in an aqueous solutions in general is not necessarily connected to the pH, organic oxidation processes imply a dropdown of pH. The reason for this is, that with rising carbon oxidation states, associated hydrogen atoms become more positively polarized and thus more easy to release from the respective compound.
As an example, the following table shows the increase in acid strength with carbon oxidation for one carbon atom-molecules:
|compound||carbon oxidation state||acid strength (pKS)|
Note: A lower pKS corresponds to the stronger acid