Ketone-body metabolism

What you will learn

• Identify the three ketone bodies and conditions that direct acetyl-CoA to their synthesis.
• Describe mitochondrial steps of ketogenesis and ketolysis.
• Explain the energy role of ketone bodies and the limits of liver and red blood cells.
• Relate fasting, insulin/glucagon, malonyl-CoA and diabetic ketoacidosis.

Course outline

1. When the liver exports energy in ketone form

   Locate the three ketone bodies, the circumstances of their production and the complementarity between producing liver and using tissues.

   18 min

2. Identifying ketone bodies and their context

   Distinguish acetoacetate, β-hydroxybutyrate and acetone, then understand why their production rises.

   28 min

3. Hepatic mitochondrial ketogenesis

   Assemble three acetyl-CoA into HMG-CoA, release acetoacetate, then separately form β-hydroxybutyrate and acetone.

   32 min

4. Extrahepatic ketolysis

   Reactivate acetoacetate in a peripheral mitochondrion, split it into two acetyl-CoA and feed the Krebs cycle.

   32 min

5. Yield and value of ketone export

   Calculate the teaching yield of β-hydroxybutyrate and understand why ketogenesis helps both liver and tissues.

   22 min

6. Overabundance, ketoacidosis and deficient production

   Distinguish markers of excessive production, understand acidosis and recognize the opposite case of hypoketosis.

   28 min

7. Directing acetyl-CoA among storage, oxidation and ketogenesis

   Connect insulin, glucagon, malonyl-CoA, CAT I and oxaloacetate to predict ketone flow.

   30 min