Final answer:
Lactic acid, when oxidized by potassium dichromate, forms pyruvic acid. This chemical process is an example of the broader biological phenomenon where lactic acid produced in muscles during intense exercise is later oxidized in the liver.
Step-by-step explanation:
When lactic acid (CH3CH(OH)CO2H) undergoes oxidation with a strong oxidizing agent like potassium dichromate (K2Cr2O7), the primary alcohol group (-CH(OH)-) in lactic acid is converted into a carboxylic acid group, resulting in the formation of pyruvic acid (CH3COCO2H). The reaction is a two-electron oxidation process, where the oxidizing agent, in this case, potassium dichromate, is reduced while the organic molecule, lactic acid, is oxidized.
The oxidation of lactic acid is significant in biological systems as well, such as during strenuous exercise when muscles run out of oxygen and lactic acid builds up, leading to muscle soreness. The lactic acid is later transported to the liver where it can be oxidized back to pyruvic acid, which can then enter the Krebs cycle for further energy production.