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YEAR 1: MCD - Metabolism > Cholesterol > Flashcards

Flashcards in Cholesterol Deck (15)
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1

What is cholesterol synthesised from?

Acetyl-CoA

2

What are the three main parts of cholesterol biosynthesis?

Generation of isopentyl pyrophosphate from acetyl-CoA Generation of squalene from isopentyl pyrophosphate Generation of cholesterol from squalene

3

What steroid hormone precursor is derived from cholesterol?

Pregnenolone – gives rise to all 5 types of steroid hormone

4

What Vitamin is synthesised from cholesterol?

Vitamin D

5

What breakdown products of cholesterol are used as bile salts?

Taurocholate and Glycocholate

6

Describe the role of cholesterol in signalling.

Cholesterol and sphingolipids form lipid rafts that are involved in localising proteins involved in signalling

7

What do the phospholipid monolayers of lipoproteins consist of?

Phospholipids
Cholesterol
Apoproteins

8

What is contained in the core of a lipoprotein?

Cholesteryl ester
Triacylglycerols

9

How are lipoproteins categorised?

Based on density Chylomicrons Very Low Intermediate Low High

10

Where is lipoprotein lipase found and what does it do?

It is found in capillary endothelial cells
Hydrolyses triacylglycerols to glycerol and fatty acids
Fatty acids are then used in beta-oxidation

11

What is the role of apoproteins in lipoproteins?

Allows the lipoprotein to be recognised by tissues

12

What are the clinical features of familial hypercholesterolaemia?

High risk of severe atherosclerosis and coronary infarction in adolescence

13

What mutation causes FH?

LDLR (LDL receptor)

14

How do statins reduce the accumulation of cholesterol? Give an example.

Statins are HMG-CoA Reductase inhibitors
Lovastatin – competitively inhibits HMG-CoA Reductase

15

What do Resins and Sequestrants do?

Hide bile acid-cholesterol complexes and prevents reabsorption by the intestines
Lowers LDL levels
Raises HDL levels