<P> Pyruvic acid (CH COCOOH) is the simplest of the alpha - keto acids, with a carboxylic acid and a ketone functional group . Pyruvate, the conjugate base, CH COCOO, is a key intermediate in several metabolic pathways . </P> <P> Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through a reaction with acetyl - CoA . It can also be used to construct the amino acid alanine and can be converted into ethanol or lactic acid via fermentation . </P> <P> Pyruvic acid supplies energy to cells through the citric acid cycle (also known as the Krebs cycle) when oxygen is present (aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking (fermentation). </P> <P> In 1834, Théophile - Jules Pelouze distilled both tartaric acid (L - tartaric acid) and racemic acid (a mix of D - and L - tartaric acid) and isolated pyrotartaric acid (methyl succinic acid) and another acid that Jöns Jacob Berzelius characterized the following year and named pyruvic acid . Pyruvic acid is a colorless liquid with a smell similar to that of acetic acid and is miscible with water . In the laboratory, pyruvic acid may be prepared by heating a mixture of tartaric acid and potassium hydrogen sulfate, by the oxidation of propylene glycol by a strong oxidizer (e.g., potassium permanganate or bleach), or by the hydrolysis of acetyl cyanide, formed by reaction of acetyl chloride with potassium cyanide: </P>

In the absence of oxygen muscle cells may convert pyruvic acid into what compound