The document summarizes ketogenesis, the formation and utilization of ketone bodies. Ketone bodies (acetone, acetoacetate, and beta-hydroxybutyrate) are synthesized in the liver through a series of reactions that condense two acetyl-CoA molecules. When glucose is in short supply, such as during starvation or diabetes, ketone bodies are released from the liver and act as an alternative fuel source for tissues like the brain. High levels of ketone bodies in the blood is known as ketonemia, while their excretion in urine is called ketonuria.

1. Unit III
Ketogenesis
Isha Rani
(Assistant Professor)
MMCP, MMU-Mullana

2. Formation and utilization of Ketone bodies:
The compound namely acetone, acetoacetate and beta-hydroxyl
butyrate are known as ketone bodies.

3. Formation (synthesis) of ketone bodies:
• Synthesis of ketone bodies is known as Ketogenesis. The synthesis of
ketone bodies occurs in liver.

5. Ketogenesis occurs through following
reations:
Two moles of acetyl CoA condense to form acetoacetyl CoA. Raection
is catalysed by thiolase.
Acetoacetyl CoA combines with other acetylCoA to produce beta-
hydroxyl b-methyl glutarylCoA. HMG CoA synthase regulates the
synthesis of ketone bodies.
HMGCoA lyase cleaves HMG CoA to acetoacetate and acetyl CoA.
Acetoacetate undergo spontaneous decarboxylate to form acetone.
Acetoacetate can be reduced by dehydrogenase to beta-hydroxyl
bytyrate.

6. Utilization of Ketone bodies:
• Ketone bodies are water soluble, so they easily transported from liver
to various tissues.
• Production of ketone bodies become high when glucose is in short
supply to tissues, mainly during starvation and diabetes mellitus.
• During prolonged starvation, ketone bodies are major fuel source for
brain and other part of CNS.

7. Ketonemia:
When rate of synthesis of ketone bodies exceeds the rate of
utilization, their concentration in blood increase, is known as
ketonemia.
Ketonuria:
Excretion of ketone bodies in urine is known as ketonuria.

8. Thank You