Investigation and risk factors for ischaemic heart disease and myocardial infarction (2)

Question 1

What are lipids?

Answer 1

Lipids are organic biomolecules which are soluble in NON-POLAR
solvents and much less soluble in water

Question 2

What are major lipids in the plasma?

Answer 2

Fatty acids (FA)
Triacylglycerols (triglycerides) (TG or TAG)
Cholesterol
Phospholipids

Question 3

What is a more efficient storage of energy: triacylglycerols or glycogen

Answer 3

triacylglycerols

Question 4

Where is triacylglycerols formed?

Answer 4

Liver

Adipose tissue

Question 5

Where do triacylglycerols come from?

Answer 5

Metabolites from glycolysis (DHAP — dihydroxyacetone phosphate) form TAGs in the FED state

Question 6

How are triacylglycerols broken down- into what?

Answer 6

Breakdown of TAGs is the first stage in fatty acid metabolism, resulting in release of FFA (free fatty acids)

Question 7

How is ATP derived from triacylglycerols

Answer 7

Resultant fatty acids then undergo B-oxidation and ATP production

Question 8

What keeps the metabolism of triacylglycerols regulated?

Answer 8

triglyceride lipase

Question 9

How is cholesterol synthesised?

Answer 9

Acetyl CoA -> HMG CoA (Intermediate)- Mevalonate

Question 10

Where is cholesterol synthesised?

Answer 10

Liver

Question 11

How is the synthesis of cholesterol regulated

Answer 11

HMG CoA Synthase

HMG CoA Reductase

Question 12

How do statins affect synthesis of cholesterol

Answer 12

statin is an HMG-CoA reductase inhibitor

stops the liver from synthesizing cholesterol

Question 13

How do lipids travel around the body?

Answer 13

Lipoproteins

Question 14

What is the lipoprotein made of structurally?

Answer 14

Surface coat

Lipid core

Question 15

What is contained in the surface coat of the lipoprotein

Answer 15

unesterified cholesterol
phospholipids
apolipoproteins

Question 16

What is contained in the lipid core of the lipoprotein

Answer 16

cholesteryl esters

triglycerides

Question 17

What is the role of apolipoproteins

Answer 17

Signals which lipoproteins it is

Question 18

What are the types of lipoproteins?

Answer 18

Chylomicrons
VLDL
IDL
LDL
HDL

Question 19

What is Chylomicrons mostly made of? least made of?

Answer 19

Triglyceride- H

Protein-L

Question 20

What is HDL mostly made of? least made of?

Answer 20

Triglyceride- L

Protein-H

Question 21

What is LDL mostly made of? least made of?

Answer 21

Cholesterol- H

Triglyceride-L

Question 22

What is chylomicrons a major transport form of?

Answer 22

Dietary fat being absorbed from the gut

Question 23

What is the chylomicrons transport pathway also known as?

Answer 23

Exogenous pathway

Question 24

What percentage of triglycerides is in chylomicrons?

Answer 24

90%

Question 25

How is triglyceride removed from chylomicrons?

Answer 25

Lipoprotein lipase

Question 26

What does chylomicrons transport?

Answer 26

cholesterol and fat-soluble vitamins Dietary fat

Question 27

What is chylomicron metabolism(exogenous pathway)?

Answer 27

Fat broken down into triglycerides so forms chylomicron triglyceride released from it by lipoprotein lipase Gets smaller becomes a chylomicron remnant and cholesteryl esters is added Cleared by liver from circulation and excreted into the bile

Question 28

In the chylomicron metabolism where does the cholesteryl ester come from?

Answer 28

HDL

Question 29

What is the VLDL metabolism known as?

Answer 29

Endogenous pathway

Question 30

What is VLDL a major transport form of?

Answer 30

Endogenous triglyceride

Question 31

Where is VLDL formed?

Answer 31

Liver

Question 32

How is triglyceride removed from VLDL?

Answer 32

Lipoprotein lipase

Question 33

VLDL metabolism?

Answer 33

Triglyceride removed by Lipoprotein lipase to make IDL More triglyceride removed with hepatic triglyceride lipase to form LDL LDL taken up by liver through LDL receptors or can be transported to peripheral tissues

Question 34

How is LDL made?

Answer 34

From VLD via IDL

Question 35

How does LDL contribute to atherosclerosis?

Answer 35

Binds to LDL receptors on cell membranes — then are broken down releasing cholesterol Uptake of LDL in the arterial wall contributes to ATHEROSCLEROSIS

Question 36

Where is HDL synthesised?

Answer 36

Liver

Question 37

What is HDL initially synthesised as?

Answer 37

Nascent HDL

Question 38

What is HDL metabolism also known as?

Answer 38

Reverse cholesterol transport

Question 39

HDL metabolism?

Answer 39

Nascent HDL delivered with cholesterol from peripheral tissues to form HDL Cholesterol esterified by Lecithin cholesterol acyl transferase Cholesterol esters are then delivered from HDL into the chylomicron remnants HDL returned to circulation

Question 40

What does Nascent HDL look like?

Answer 40

flat cylinder

Question 41

What are the lipid disorders that we need to know?

Answer 41

Familial hypercholesterolaemia Type III hyperlipidaemia Hypertriglyceridemia