(1) A colorless or yellowish, syrupy, water-soluble liquid, which is a byproduct of anaerobic glucose metabolism.
(2) An intermediate product of carbohydrate metabolism (anaerobic metabolism), derived chiefly from muscle cells and red blood cells.
(3) A clear, odorless, hygroscopic organic acid abundant in many fruits, wine and sour milk.
Lactid acid level may be measured in the bloodstream in conditions of metabolic acidosis. Level of lactic acid rises during conditions of oxygen deprivation, such as shock, heart failure, and lung disease. The level also increases normally during exercise. Normal lactic acid levels are between 4.5 and 19.8 mg/dl
Lactic acid occurs in the following (optically isomeric) forms:
- dextrorotatory form – present normally in blood and muscle tissue as a product of the anaerobic metabolism of glucose
- levorotatory form – obtained by biological fermentation of sucrose.
- racemic form – produced by bacterial fermentation, or by synthetic process for use mainly in dyeing and textile printing, as a flavoring and preservative agent in food, and in medicine.
IUPAC name: 2-hydroxypropanoic acid
Molecular formula: C3H6O3
- milk acid
- E270 (a preservative agent)