Pyruvic acid (CH3COCO2H) is an alpha-keto acid, of the keto acid group. The anion of pyruvic acid is called pyruvate.
In the laboratory, pyruvic acid may be prepared by heating tartaric acid mixed with potassium hydrogen sulphate, or by the hydrolysis of acetyl cyanide formed from acetyl chloride, by reaction with potassium cyanide:
CH3COCl + KCN → CH3COCN
CH3COCN → CH3COCOOH
It is created by the body when sugars are metabolised. A molecule of glucose breaks down into two pyruvic acid molecules, and these are then used to provide further energy, in one of two ways. Provided that sufficient oxygen is available, pyruvic acid is broken down to carbon dioxide in a series of reactions known as the Krebs cycle. These reactions are named after Sir Hans Krebs, the biochemist who was awarded the 1953 Nobel Prize for physiology, jointly with Fritz Lipmann, for research into metabolic processes. The cycle is also called the Citric acid cycle, because citric acid is one of the intermediate compounds formed as the cycle takes place. If insufficient oxygen is available, the acid is broken down anaerobically, creating lactic acid in animals and ethanol in plants.