Lipids

Question 1

Are lipids soluble in water?

Answer 1

No

Question 2

What are lipids essential for?

Answer 2

membrane integrity and biogenesis

Question 3

How are non polar lipids transported?

Answer 3

In lipoproteins e.g. HDL, LDL

Question 4

Is the lipoprotein core hydrophobic or hydophilic, and what does it contain?

Answer 4

Hydrophobic, contains esterified cholesterol triglycerides

Question 5

Is the lipoprotein coat hydrophobic or hydrophilic?

Answer 5

Hydrophilic

Question 6

What is the lipoprotein coat a monolayer of?

Answer 6

Amphipathic cholesterol, phospholipids and one or more apoproteins

Question 7

What are the 4 main lipoproteins?

Answer 7

HDL, LDL, VLDL and Chylomicrons

Question 8

What are the 3 parts of the life cycle of Apo-B containing lipoproteins?

Answer 8

assembly, intravascular metabolism and receptor mediated clearance

Question 9

Where do Apo-B containing lipoproteins deliver triglycerides?

Answer 9

To muscle for ATP biogenesis, and to adipocytes for storage

Question 10

Where are chylomicrons formed?

Answer 10

intestinal cells

Question 11

What do chylomicrons deliver and by what pathway?

Answer 11

dietary triglycerides, by exogenous pathway

Question 12

Where is VLDL formed?

Answer 12

Liver cells

Question 13

What does VLDL transport?

Answer 13

Triglycerides synthesised in the endogenous pathway

Question 14

What protein do Apo-B containing lipoproteins contain?

Answer 14

NPCILI

Question 15

How does chylomicron exit the enterocyte?

Answer 15

exocytosis following addition of second apoprotein

Question 16

What is the chlyomicron carried in after it leaves the enterocyte?

Answer 16

Lymph via the thoracic duct

Question 17

What are free fatty acids in VLDL derived from?

Answer 17

adipose tissue and de novo synthesis

Question 18

What activates VLDL?

Answer 18

transfer of apoCII from HDL particles

Question 19

What does ApoC11 facilitate the binding of?

Answer 19

Chylomicrons and VLDL to LPL

Question 20

What does LPL hydrolyse?

Answer 20

core triglycerides to free fatty acids and glycerol which enter tissues

Question 21

Particles depleted of triglycerides are termed what?

Answer 21

Chylomicron and VLDL remnants

Question 22

What are these remnants further metabolised by?

Answer 22

hepatic lipase in the liver

Question 23

What are they then cleared by?

Answer 23

Receptor mediated enterocytes into hepatocytes

Question 24

What does released cholesterol cause?

Answer 24

Inhibition of HMG-CoA reductase

Question 25

What is LDL oxidised to?

Answer 25

Atherogenic OXLDL

Question 26

What do monocytes migrate across the endothelium to and what do they become?

Answer 26

Intima, become macrophages

Question 27

What are these macrophages converted to?

Answer 27

Cholesterol laden foam cells which form a fatty streak

Question 28

What is then released?

Answer 28

Inflammatory substances

Question 29

What is formed?

Answer 29

Atheromatous plaque consisting of lipid core (dead foam cells) and fibrous cap (product of dead foam cells)

Question 30

What is the only organ with the capacity to eliminate cholesterol?

Answer 30

Liver

Question 31

Where is HDL mainly formed?

Answer 31

Liver

Question 32

What type HDL matures into what type?

Answer 32

pre-B-HDL to spherical alpha-HDL

Question 33

What does the mature form of HDL accept?

Answer 33

excess cholesterol from plasma membrane of cells (which it delivers to liver - reverse cholesterol transport)

Question 34

Subset of what is associated with increased risk of ischaemic heart disease?

Answer 34

Subset of type IIa hyperliproteinaemia

Question 35

What is the mediator or transfer of esterin plasma?

Answer 35

CETP