Cholesterol synthesis And Regulation

Question 1

Cholesterol can be described as a?

Answer 1

Cyclopentanoperhydrophenanthene

Question 2

Concerning cholesterol…

Answer 2

It is the hydroxyl group attachment that makes the molecule to be referred to as a molecule that exhibits both hydrophilic and hydrophobic properties

Question 3

What is the precursor molecule for cholesterol synthesis?

Answer 3

Acetyl Co A

Question 4

What enzyme reduces HMG - COA to become a mevalonate

Answer 4

HMG-COA reductase

Question 5

What is the difference between lanosterol and cholesterol ?

Answer 5

The ring in lanosterol is closed while that of cholesterol is open

Question 6

What is the regulatory enzyme of cholesterol biosynthesis ?

Answer 6

HMG Co A reductase

Question 7

Mechanisms by which cholesterol regulates its metabolism ?

Answer 7

1. Feedback mechanism
2. Hormonal regulation
3. Inhibition by drugs
4. Bile acids and fasting

Question 8

__ inhibits the action of HMG co a reductase by phosphorylation?

Answer 8

Glucagon

Question 9

____ and ____ activate HMG reductase by dephosphorylation

Answer 9

Insulin and thyroxine

Question 10

___ and ___ drugs inhibit the action of HMG co A reductase ?

Answer 10

Compactin and lovestatin

Question 11

Statin reacts with HMG Reductase to form

Answer 11

HMG Co A reductase complex

Question 12

Biochemical importance of cholesterol?

Answer 12

1. Diabetes Mellitus
2. Obesity
3. Obstructive jaundice
4. Artherosclerosis and coronary heart disease

Question 13

IUPAC name for cholesterol

Answer 13

(3B)-cholesten-5-en-3-ol