Statement true about ketone bodies is
KETOSISUnder ceain metabolic conditions associated with a high rate of fatty acid oxidation, liver produces considerable quantities of compounds like acetoacetate and b-OH butyric acid, which pass by diffusion into the blood. Acetoacetate continually undergoes spontaneous decarboxylation to produce acetone. These three substances are collectively known as "ketone bodies" (or "acetone bodies"). Sometimes also called as "ketones", which is rather a misnomer.Concentration of Ketone BodiesConcentration of total ketone bodies in the blood of well fed individuals does not normally exceed 1 mg/100 ml (as acetone equivalents).Urine: Loss urine is usually less than 1 mg/ 24 hrs in humans.Ketoacidosis: Acetoacetic acid and b-OH-butyric acid are moderately strong acids. They are buffered when present in blood and tissues, entailing some loss of buffer cations, which progressively depletes the alkali reserve| causing ketoacidosis.Note: This may be fatal in uncontrolled diabetes mellitusCauses1. Starvation: Simplest form of ketosis occurs in starvation.Mechanism: Involves depletion of available carbohydrate reserve, coupled with mobilisation of FFA and oxidation to produce energy.2. In Pathologic States* In Diabetes mellitus: Clinical and experimental.* In some types of alkalosis: Ketosis may develop.* Pregnancy toxaemia in sheep and in lactating cattle.3. In prolonged ether anaesthesia.4. Other non-pathologic forms of ketosis are found under conditions of:* High fat feeding.* After severe exercise in the postabsorptive state.5. Injection of anterior pituitary extracts. Site of Formation and Fate Liver appears to be the only organ which produces ketone bodies and add to the blood. Extrahepatic tissues can pick up ketone bodies from the circulating blood and utilise them as respiratory substrates. Net flow of ketone bodies from the liver to extrahepatic tissues results from an active enzymatic mechanism in the liver which exists, for the production of ketone bodies, coupled with very low activity of the enzymes rather than their absence, responsible for their degradation or utilisation. The reverse situation exists in extrahepatic tissuesRef: M.N.Chatterjee Textbook of Biochemistry 8th edition pg no: 425
Major source of energy supply to liver
They are derived from cholesterol
Their levels increase in starvation
Levels are raised in fed state
Metabolism of lipid