Cholesterol Biosynthesis and Function

Dr. Puja Ji introduces cholesterol, a key component of lipid metabolism, detailing its structure, transport, and biosynthesis. Cholesterol is synthesized in the body via the denovo pathway, involving key enzymes like HMG CoA reductase, which is regulated by feedback inhibition and inhibited by statins. The video also covers the clinical significance of LCAT enzyme in cholesterol transport and the importance of cholesterol in synthesizing vitamin D and bile acids. Methods for detecting cholesterol are also discussed.

What is the molecular formula of cholesterol?

• C15H24O

• C27H45O

• C18H36O2

• C20H30O

What percentage of cholesterol is transported in an esterified form?

• 50%

• 70%

• 30%

• 90%

Which enzyme is responsible for the synthesis of cholesterol esters?

• LCAT

• HMG CoA reductase

• Amylase

• Lipase

What disease is associated with the absence of the LCAT enzyme?

• Niemann-Pick disease

• Fabry disease

• Gaucher's disease

• Norms disease

Where does the biosynthesis of cholesterol primarily occur?

• Nucleus

• Golgi apparatus

• Cytosolic fraction of the liver

• Mitochondria

What is the rate-limiting enzyme in cholesterol biosynthesis?

• Fatty acid synthase

• Acetyl-CoA carboxylase

• HMG CoA reductase

• HMG CoA synthase

Statins are competitive inhibitors of which enzyme?

• Amylase

• Lipase

• LCAT

• HMG CoA reductase

Cholesterol is a precursor for which vitamin?

• Vitamin E

• Vitamin D

• Vitamin C

• Vitamin A

What is the primary function of bile acids synthesized from cholesterol?

• DNA replication

• Carbohydrate metabolism

• Emulsification of fats

• Protein synthesis

Which reaction is used to detect cholesterol?

• Liberman-Burchard reaction

• Biuret test

• Fehling's test

• Benedict's test