Bile Acid Synthesis | Classic and Alternative Pathways | Primary and Secondary Bile Acids

The video tutorial explains bile acid synthesis from cholesterol in the liver, detailing the classic and alternative pathways. It covers the structural modifications of cholesterol, the role of enzymes like CYP 7A and CYP 27A1, and the formation of primary bile acids. The tutorial also discusses the conjugation of bile acids to amino acids, forming bile salts, and their function in digestion. Finally, it describes the conversion of primary bile acids to secondary bile acids by bacterial enzymes.

What percentage of liver cholesterol is typically converted into bile acids?

• 70-80%

• 10-20%

• 30-40%

• 50-60%

Which of the following is NOT a function of bile acids?

• Emulsifying fats

• Aiding in fat digestion

• Absorbing water-soluble vitamins

• Preventing cholesterol precipitation

What is the role of cholesterol 7A hydroxylase in bile acid synthesis?

• It breaks down bile acids

• It converts cholesterol to 7A hydroxy cholesterol

• It removes cholesterol from the liver

• It synthesizes cholesterol

Which enzyme is crucial in the alternative pathway of bile acid synthesis?

• CYP 8B1

• CYP 7A

• CYP 7B1

• CYP 27A1

What is the primary bile acid produced exclusively in the alternative pathway?

• Lithocholic acid

• Deoxycholic acid

• Chenodeoxycholic acid

• Cholic acid

What is the purpose of conjugating bile acids with amino acids?

• To decrease their PKA

• To increase their molecular weight

• To make them more acidic

• To increase their solubility in water

Which amino acid is NOT used to conjugate bile acids?

• Lysine

• Taurine

• Glycine

• Alanine

What happens to bile acids in the large intestine?

• They are absorbed into the bloodstream

• They are converted into secondary bile acids

• They are excreted unchanged

• They are converted back to cholesterol

Which of the following is a secondary bile acid?

• Cholic acid

• Chenodeoxycholic acid

• Glycocholic acid

• Deoxycholic acid

What is the effect of conjugating bile acids on their emulsifying ability?

• It increases their ability

• It makes them insoluble

• It has no effect

• It decreases their ability