Liver Function I - Seidler

Question 1

What goes into forming isoprenoids

Answer 1

3 Acetyl CoA’s come together to form Isopentenyl pyrophosphate (IPP) - (active isoprene) that serves as the building blocks for the synthesis of all isoprenoids

Question 2

What is the building blocks of isoprenoids?

Answer 2

Isopentenyl pyrophosphate (IPP)

Question 3

3 groups of isoprenoids

Answer 3

1. Steroids - cholesterol, bile acids, steroid hormones
2. Lipid-soluble vitamins - A,D,E,K
3. Other - ubiquinone, dolichol, heme tails, lipid anchors

Question 4

What can arise due to abnormalities in the synthesis and processing of lipoproteins?

Answer 4

Hyperlipoproteinemias (typically elevated cholesterol) or hypolipo-proteinemias (typically decreased cholesterol)

Question 5

All steroids contain?

Answer 5

Sterane ring

- four rings combined

Question 6

Examples of steroids

Answer 6

Cholesterol
Estradiol
Cholic acid

Question 7

How are sterols different?

Answer 7

They are steroid molecules with hydroxyl groups

Question 8

Structural features of cholesterol?

Answer 8

27 carbon molecule

17 C make up sterane ring

Question 9

Which precursor of cholesterol is a linear structure?

Answer 9

Squalene

Question 10

What is the fate of cholesterol in all tissues?

Answer 10

Cholesterol is incorporated into cellular membranes

Question 11

What is the fate of cholesterol in liver?

Answer 11

Cholesterol used to synthesize bile acids

Question 12

What is the fate of cholesterol in adrenal glands, ovaries and testes?

Answer 12

Cholesterol used to synthesize steroid hormones

Question 13

Fate of cholesterol in skin?

Answer 13

Used to synthesize vitamin D

Question 14

Effect of statins?

Answer 14

Competitively inhibit HMG CoA reductase (HMGR)

Question 15

Bile salt and cholesterol

Answer 15

Micelles, essential for absorption of lipids and lipid-soluble vitamins by intestinal cells