Ketone bodies are three chemicals that are produced as by-products when fatty acids are broken down for energy. Contrary to what the name "bodies" may suggest, these are soluble compounds, not particles. Any production of these compounds is called ketogenesis, and this is necessary in small amounts. But, when excess ketone bodies accumulate, this abnormal (but not necessarily harmful) state is called ketosis. When even larger amounts of ketone bodies accumulate such that the body's pH is lowered to dangerously acidic levels, this state is called ketoacidosis. Image File history File links Ketonebodies. ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid (or organic acid), often with a long aliphatic tail (long chains), either saturated or unsaturated. ... Ketogenesis is the process by which ketone bodies are produced as a result of fatty acid breakdown. ... Ketosis (IPA pronunciation: ) was identified by Dr. Stephen Moody in 1969 and is a stage in metabolism occurring when the liver has been depleted of stored glycogen and switches to a chronic fasting mode during long periods of starvation. ... Ketoacidosis is a type of metabolic acidosis which is caused by high concentrations of keto acids, formed by the deamination of amino acids. ...

The three ketone bodies are acetoacetate, beta-hydroxybutyrate and acetone. Beta-hydroxybutyrate is not technically a ketone (they are called ketone bodies because they come from ketones). Acetoacetic acid (also known as 3-oxobutanoic acid or diacetic acid) is a beta-keto acid of the keto acid group, its empirical formula is C4H6O3 or CH3COCH2COOH. It is a strong organic acid and can be produced in the human liver under certain conditions of poor metabolism leading to... Beta-hydroxybutyrate, acetoacetate, and acetone collectively are called ketone bodies. ... In chemistry, acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is the simplest representative of the ketones. ... Beta-hydroxybutyrate, acetoacetate, and acetone collectively are called ketone bodies. ... Ketone group A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a chemical compound that contains this functional group. ... A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a compound that contains this functional group. ...

Ketone bodies are produced from acetyl-CoA (see ketogenesis) mainly in the mitochondrial matrix of liver cells when carbohydrates are so scarce that energy must be obtained from breaking down fatty acids. Acetyl Coenzyme A Acetyl-CoA Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidization of fatty acids, and the oxidation of pyruvate in the citric acid cycle. ... Ketogenesis is the process by which ketone bodies are produced as a result of fatty acid breakdown. ... ... The liver is an organ in living beings, including humans. ... Lactose is a disaccharide found in milk. ... Fatty acids are an important source of energy for many organisms. ...

Ketone bodies can also be used for energy. Ketone bodies are transported from the liver to other tissues, where acetoacetate and beta-hydroxybutyrate can be reconverted to acetyl-CoA to produce energy. The heart gets much of its energy from ketone bodies, although it also uses a lot of fatty acids. The brain gets its energy from ketone bodies when insufficient glucose is available (e.g. when fasting). In the event of low blood glucose, most other tissues have additional energy sources besides ketone bodies (such as fatty acids) but the brain does not. After the diet has been changed to lower blood glucose for 3 days, the brain gets 30% of its energy from ketone bodies. After 40 days, this goes up to 70% (during the initial stages the brain does not burn ketones, since they are an important substrate for lipid synthesis in the brain). The brain retains some need for glucose, because ketone bodies can be broken down for energy only in the mitochondria, and brain cells' long thin axons are too far from mitochondria. Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... In medicine, blood sugar is a term used to refer to levels of glucose in the blood. ... An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ...

Acetone is formed from spontaneous decarboxylation of acetoacetate. In a corresponding manner, the levels of acetone are much lower than those of the other two types of ketone bodies. And, unlike the other two, acetone cannot be converted back to acetyl-CoA, so it is excreted in the urine and exhaled (it can be exhaled because it has a high vapor pressure and thus evaporates easily). The exhalation of acetone is responsible for the characteristic "fruity" odour of the breath of persons in ketotic states. In chemistry, acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is the simplest representative of the ketones. ... A Decarboxylation is any chemical reaction in which a carboxyl group (-COOH) is split off from a compound as carbon dioxide (CO2). ... To meet Wikipedias quality standards, this article or section may require cleanup. ... In chemistry and physics, Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... In chemistry, acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is the simplest representative of the ketones. ...

Both acetoacetate and beta-hydroxybutyrate are acidic, and, if levels of these ketone bodies are too high, the pH of the blood drops, resulting in ketoacidosis. This happens in untreated Type I diabetes (see diabetic ketoacidosis), and also in alcoholics after binge drinking and subsequent starvation (see alcoholic ketoacidosis). For other uses, see Acid (disambiguation). ... . The initial letter is shown capitalized due to technical restrictions. ... This article is about the disease that features high blood sugar. ... Diabetic ketoacidosis (DKA) is one consequence of untreated diabetes mellitus (chronic high blood sugar, or hyperglycemia), and is linked to an impaired glucose cycle. ... King Alcohol and his Prime Minister circa 1820 Alcoholism is the consumption of or preoccupation with alcoholic beverages to the extent that this behavior interferes with the alcoholics normal personal, family, social, or work life. ... Ketoacidosis is a type of metabolic acidosis which is caused by high concentrations of keto acids, formed by the deamination of amino acids. ...

See also

• Fatty acid metabolism
• Ketogenesis
• Ketosis

Fatty acids are an important source of energy for many organisms. ... Ketogenesis is the process by which ketone bodies are produced as a result of fatty acid breakdown. ... Ketosis (IPA pronunciation: ) was identified by Dr. Stephen Moody in 1969 and is a stage in metabolism occurring when the liver has been depleted of stored glycogen and switches to a chronic fasting mode during long periods of starvation. ...

References

• Atkins Nutritionals, Inc. Lipolysis and Ketosis
• Diabetic Ketoacidosis
• Fat metabolism
• Breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals, American Journal of Clinical Nutrition.
• NHS Direct Online Health Encyclopaedia, Ketosis
• BioCarta Pathways Formation of Ketone Bodies