Ketone bodies

Definition

Ketone bodies are three water-soluble molecules (acetoacetate, beta-hydroxybutyrate, and acetone) that are produced by the liver from fatty acids during periods of low food intake (fasting), carbohydrate restrictive diets, starvation, or prolonged intense exercise. They serve as an alternative energy source for the brain and other tissues when glucose is not readily available.

Related terms

Lipolysis:

The process of breaking down triglycerides into glycerol and free fatty acids; it's an essential step before the liver can produce ketone bodies.

Beta: oxidation - A metabolic process where fatty acids are broken down in the mitochondria to generate acetyl-CoA, which is then used to produce ketone bodies in the liver.

Gluconeogenesis:

A metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates; it works alongside ketogenesis during periods of low carbohydrate availability.