2.4-LipoProteins & Lipid Transport

Question 1

What are the 5 lipid transporters we discussed? Does a High Density LipoProtein have high lipid content or high protein content?

Answer 1

1.ChyloMicrons 2. VLDLs 3.IDL 4.LDL 5.HDL…..HDL will have High Protein Density (therefore low lipid density)

Question 2

Why are chylomicrons & VLDLs so similar? What is their only difference?

Answer 2

Chylomicrons and VLDLs have a high ratio of lipids in them, like marshmallows :) The only difference is chylomicrons=dietary lipids vs VLDLs=synthesized lipids

Question 3

Which Lipoprotein goes from cells to liver? Which goes from liver to cells?

Answer 3

Cells to Liver=HDL Liver to Cells=LDL

Question 4

What are the two AlipoProteins we discussed on chylomicrons in the intestine?

Answer 4

Apo B48 and Apo A

Question 5

Where to Chylomicrons enter circulation? What happens from there?

Answer 5

Enter through the lymphatic system, then thru the thoracic duct and then the subclavian vein

Question 6

What is the major reservoir for apolipoproteins? Which Lipoproteins?

Answer 6

HDL…Apc CII and Apo E

Question 7

What enzyme does Apo CII activate? Where can I find an Apo CII?

Answer 7

LipoProtein Lipase…Apo CII is on ChyloMicrons & VLDL

Question 8

What is the role of lipoprotein lipase? Where do the products go?

Answer 8

Breaks down TAGs to Glycerol (to Liver) and FFAs (Adipose tissues)

Question 9

Where can I find a good ole LipoProtein Lipase?

Answer 9

On the endothelial Wall of a blood capillary

Question 10

What Apo ligand allows ChyloMicron Remnants to be endocytosed back into the Liver?

Answer 10

Apolipoprotein E

Question 11

Which apolipoprotein do they look at when checking for alzheimers?

Answer 11

Apo E

Question 12

How much TAG is removed when we go from a Chylomicron to a ChyloMicron Remnant?

Answer 12

90% of the TAGs removed!

Question 13

How long is a ChyloMicron half life?

Answer 13

Less then an hour

Question 14

Where do 80% of TAGs from ChyloMicrons go? 20%?

Answer 14

80% Adipose, heart, muscle 20% liver

Question 15

What enzyme is used toTRAP fatty acids in a cell? How much ATP do we need to do this?

Answer 15

Fatty Acyl-CoA Synthetase…2 ATP used

Question 16

What is the significant alipoprotein on the VLDL from the Liver? What was the similar form of this in the intestine on CMs?

Answer 16

ApoB-100…ApoB-48 on CMs in the intestine

Question 17

What two ApoLipos are used on VLDLs? THINK ChyloMicrons!

Answer 17

Apo C-II and Apo E

Question 18

What happens in the magical of turing VLDL to LDL? What is the core of LDL as a result?

Answer 18

Removing Fatty Acids turns VLDL to LDL. Dense core of cholesterol is the result

Question 19

Who is our Cholesterol delivery boy? What is the ligand that helps it bind to receptor cells?

Answer 19

LDL…ApoB-100

Question 20

What type of fat blocks hepatocyte cellular receptors for LDL? What is the result?

Answer 20

Saturated fat…results in raising blood cholesterol (SO Sat Fat blocks LDL entering, SO Liver makes more cholesterol because it thinks there is not enough in body)

Question 21

What is the enzyme that regulated Cholesterol Synthesis in the liver?

Answer 21

HMG CoA Reductase

Question 22

What does HDL Alipo A1 activate to scavenge cholesterol? (2 names)

Answer 22

LCAT and PCAT

Question 23

Which protein transfers TAGs with cholesteryl esters on VLDLs?

Answer 23

CETP (Cholestetyl Ester Transfer Protein (Weird name, i know)

Question 24

What is the consequence of a decrease in lipoprotein lipase activity?

Answer 24

Elevation of Plasma Chylomicrons and VLDL?