The video discusses the biosynthesis of ketone bodies in the liver, particularly during fasting states when glucose is scarce. It explains the conversion of fatty acids to acetyl-CoA and the subsequent formation of ketone bodies like acetoacetate, acetone, and beta-hydroxybutyrate. The video also covers the metabolic pathways of HMG-CoA in different states and introduces the catabolism of ketone bodies, highlighting the liver's role in production but not utilization.

What triggers the liver to switch to fatty acid metabolism and produce ketone bodies?

• Increased carbohydrate consumption

• High blood sugar levels

• Fasting state with low glucose availability

• Excessive protein intake

Which enzyme catalyzes the condensation of two acetyl-CoA molecules to form acetoacetyl-CoA?

• Thiolase

• HMG-CoA synthase

• Beta-hydroxybutyrate dehydrogenase

• Acetoacetate decarboxylase

What is the role of HMG-CoA lyase in ketone body biosynthesis?

• Converts HMG-CoA to mevalonate

• Reduces acetoacetate to beta-hydroxybutyrate

• Forms acetoacetate from HMG-CoA

• Catalyzes the condensation of acetyl-CoA

Which of the following is a true ketone body?

• Acetone

• Beta-hydroxybutyrate

• Acetoacetate

• Mevalonate

How is beta-hydroxybutyrate formed from acetoacetate?

• By reduction using NADH

• By oxidation

• By decarboxylation

• By condensation with acetyl-CoA

What happens to acetone in the body?

• It is exhaled through the lungs

• It is stored in the liver

• It is converted to glucose

• It is used directly by the brain

Which tissues can utilize ketone bodies for energy production?

• Skeletal muscle

• Adipose tissue

• Liver

• Pancreas