ket(o)- Also keton-.
Ketones are organic chemical compounds that contain a carbonyl group —CO— bonded to two alkyl groups and whose names have the systematic ending -one. The production of ketones during the metabolism of fats is termed ketogenesis; ketosis is the presence of raised levels of ketones in the body. The form sometimes appears as keton- before a vowel, as in phenylketonuria, an inherited inability to metabolize phenylalanine.
In chemistry, a keto acid is a compound whose molecule contains both a carboxyl group (—COOH) and a ketone group, such as α–ketoglutaric acid, which occurs in the metabolism of proteins; ketamine is a synthetic compound used as an anaesthetic and analgesic drug and also (illicitly) as an hallucinogen.