Bile Acids Flashcards

Flashcards about the structure, synthesis, function, regulation of synthesis, and circulation of bile acids.

In the liver.

Where are bile acids synthesized?

Cholesterol.

What are bile acids synthesized from?

In the gallbladder.

Where are bile acids stored?

Help with fat digestion.

What role do bile acids play?

By absorbing them from the intestines (enterohepatic circulation).

How are bile acids recycled?

Phospholipids, cholesterol, and bile acids/salts.

What does bile contain?

Three carbons are removed, resulting in 24 carbons.

How many carbons are removed from the cholesterol side chain in bile acid synthesis?

Catalyzed by 7-alpha hydroxylase (CYP7A1).

What is the first and rate-limiting step in bile acid synthesis?

Liver X receptor (LXR).

What regulates the transcription of the gene for 7-alpha hydroxylase?

Glycine or taurine.

What are bile acids conjugated to before being secreted from the liver?

Formed in the intestines by anaerobic bacteria removing the 7-alpha hydroxyl group from primary bile acids. Glycine and taurine are also removed.

What are secondary bile acids?

Act as detergents, forming emulsions in the digestive tract to aid fat digestion and absorption.

How do bile acids/salts aid in fat digestion?

Greater than 95%.

How much of the bile acids that enter intestine are reabsorbed?

Ileum.

Where are bile acids reabsorbed?

Binds bile acids and inhibits the enterohepatic circulation, increasing bile acid synthesis and LDL receptor production

What is the mechanism of action of Cholestyramine?

Low bile salt concentration or high cholesterol/phospholipid ratio.

What conditions can cause Cholesterol-rich gallstones?