Keto Genesis 4f2ge

What is this sort of a diet?

KETOGENESIS Dr. Angel Mercy Sylus 26.04.19

SPECIFIC LEARNING OBJECTIVES At the end of the session, you will be able to 1. List the types of ketone bodies 2. Indicate the conditions in which their synthesis is favored 3. Describe the steps of ketogenesis

KETONE BODIES • Water-soluble, transportable form of acetyl units • Source of energy : Cardiac muscle, kidneys, brain 20%

Acetoacetate

78% Beta hydroxy butyrate

2%

Acetone

KETONE BODIES • Energy source for tissues during » Starvation » Uncontrolled Type 1 Diabetes Mellitus » Low carbohydrate with high fat diet • Circulatory level of ketone bodies : In a normal well fed person  ≤ 1mg/dl In prolonged starvation  up to 500mg/dl

MECHANISM Glucose G LYC O LY S I S

Pyruvate

Fatty acids β - O X I D AT I O N

Acetyl CoA

GLUCONEOGENESIS

Oxaloacetate

TCA CYCLE

MECHANISM STARVATION

UNCONTROLLED TYPE 1 DM

• INSULIN

• GLUCAGON • EPINEPHRINE

LOW CHO HIGH FAT DIET

• GROWTH HORMONE

MECHANISM Glucose G LYC O LY S I S

Pyruvate

Fatty acids β - O X I D AT I O N

Acetyl CoA

GLUCONEOGENESIS

Oxaloacetate

Ketone Body Synthesis TCA CYCLE

KETOGENESIS • Site : Liver (90%), Kidney (10%) • Cellular site : Mitochondria • Substrates : Acetyl CoA

• Products : Acetoacetate – Primary Betahydroxy butyrate & Acetone – Secondary

KETOGENESIS Acetyl CoA Thiolase

Acetyl CoA CoA-SH

Aceto-acetyl CoA Rate – limiting

HMG CoA synthase

Acetyl CoA H₂O CoA-SH

HMG CoA (3-Hydroxy 3-methyl glutaryl CoA)

KETOGENESIS HMG CoA HMG CoA lyase

Acetyl CoA

Acetoacetate NADH + H⁺

Dehydrogenase NAD

Beta hydroxy butyrate

Non-enzymatic decarboxylation CO₂

Acetone

KETOGENESIS ? ?

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SUMMARY • Ketone bodies are a major source of energy during starvation and uncontrolled type 1 DM • The ketone bodies are acetoacetate, acetone and beta-hydroxybutryate • Synthesized in liver mitochondria • Rate limiting enzyme is HMG CoA synthase

Thank you…