Ketone Bodies: Metabolism and Functions

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What is the main function of ketone bodies in the body?

Enhance muscle growth and repair

Serve as alternative fuel when glucose is scarce (correct)

Regulate hormone production in the liver

Act as structural components of cell membranes

Which of the following compounds are collectively known as ketone bodies?

Acetyl CoA, pyruvate, succinyl-CoA

Acetate, propionate, butyrate

Lactate, malate, citrate

Acetoacetate, β-hydroxybutyrate, acetone (correct)

During which state does the hepatic production of acetoacetate and β-hydroxybutyrate increase significantly?

Exercise state

Postprandial state

Sleeping state

Starvation state (correct)

What triggers the process of ketone body synthesis (ketogenesis) in the liver?

Excess acetyl CoA from β-oxidation Signup and view all the answers

In what conditions do the concentrations of acetoacetate and β-hydroxybutyrate remain low in the blood?

During the fed state Signup and view all the answers

Which statement about ketone bodies is true?

They are a main source of energy for the brain during prolonged starvation Signup and view all the answers

What is the role of ketone bodies in the body?

They can be used by extrahepatic tissues to meet energy needs Signup and view all the answers

Which enzyme is considered the rate-limiting step in ketone body synthesis?

HMG-CoA synthase Signup and view all the answers

How does glucagon hormone affect HMG-CoA synthase activity?

Activates HMG-CoA synthase Signup and view all the answers

What happens to HMG-CoA synthase activity when CoASH levels in the liver are high?

HMG-CoA synthase is inhibited Signup and view all the answers

How do ketone bodies contribute to sparing glucose during fasting?

Ketone bodies can be used as an alternative fuel source instead of glucose Signup and view all the answers

Which tissue can use ketone bodies to meet its energy needs?

Brain Signup and view all the answers

What triggers an increase in the production of ketone bodies during fasting?

Insulin deficiency Signup and view all the answers

In which tissues are ketone bodies utilized as a fuel during prolonged starvation?

Muscles, brain, and kidneys Signup and view all the answers

What happens when the rate of formation of ketone bodies exceeds their utilization?

Ketonemia and ketonuria occur Signup and view all the answers

Which enzyme is responsible for reactivating acetoacetate to form acetoacetyl CoA in nonhepatic tissues?

Thiophorase Signup and view all the answers

What is the main cause of ketosis in diabetic patients with uncontrolled blood glucose?

Insulin deficiency Signup and view all the answers

How does the lack of insulin contribute to increased ketone body synthesis?

It decreases glucose utilization Signup and view all the answers

What process is increased as a result of following a strict ketogenic diet?

Lipolysis Signup and view all the answers

Which of the following is a consequence of a significant reduction in blood sugar levels due to a ketogenic diet?

Hypoglycemia Signup and view all the answers

What is the primary metabolic role of ketone bodies in the body?

Fuel for the brain and muscles Signup and view all the answers

What happens if there is a progressive depletion of the alkali reserve in the blood due to the presence of certain acids?

Ketoacidosis Signup and view all the answers

Which condition is associated with uncontrolled diabetes and is characterized by high levels of ketone bodies in the blood?

Diabetic ketoacidosis (DKA) Signup and view all the answers

What is the major consequence of high fat and protein intake in ketogenic diets?