Users' questions

How is cholesterol synthesized?

How is cholesterol synthesized?

Cholesterol is synthesized via a cascade of enzymatic reactions known as the mevalonate pathway. This series of reactions is primarily regulated by a rate-limiting step involving the conversion of hydroxyl-methyl glutaryl-coenzyme A (HMG-CoA) into mevalonate.

Which compound inhibits cholesterol synthesis in human?

Pravastatin inhibited the cholesterol synthesis in human hepatoma cell line Hep G2 less than simvastatin and lovastatin, which is reflected in the upregulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase and squalene synthase.

How are statins used to control cholesterol synthesis?

The statins thereby inhibit the synthesis of mevalonate and slow the rate of cholesterol synthesis. To account for the reduction of cholesterol synthesis, cells increase the rate of uptake of cholesterol from outside thereby lowering the amount of cholesterol in the blood. Elevated levels of cholesterol target HMG-CoA reductase for proteolysis.

How are cellular cholesterol synthesis and uptake coordinated?

Both mechanisms contribute to total cellular cholesterol. The activities of the two pathways are coordinated. For example, inhibiting the synthesis of cholesterol stimulates the uptake of cholesterol from the blood via endocytosis.

How are isoprenoid intermediates diverted in cholesterol biosynthesis?

The isoprenoid intermediates of cholesterol biosynthesis can be diverted to other synthesis reactions, such as those for dolichol (used in the synthesis of N -linked glycoproteins ), coenzyme Q (of the oxidative phosphorylation pathway), or the side chain of heme- a.

What are the 5 stages of cholesterol biosynthesis?

Identify the five stages in the biosynthesis of cholesterol from acetyl-CoA. Understand the role of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase) in controlling the rate of cholesterol synthesis and explain the mechanisms by which its activity is regulated.