2.4 Lipoproteins and Lipid transport

Question 0

Which molecule of lipid transport has the highest amount of TAGs as in weight?

Answer 0

Chylomicrons

Question 1

What major tissue and organ destination does Chylomicron have?

Answer 1

Give up FFA to Adipose tissue, muscle and heart

Question 2

Which lipid transport molecule has the highest % of cholesterols contained in it

Answer 2

LDL

Question 3

Which molecule has the lowest density based on low protein/lipid ration

Answer 3

Chylomicrons –> VLDL –> IDL –> LDL

Question 4

What is HDL’s target tissue?

Answer 4

the Liver

Question 5

What two apolipoproteins do chylomicrons receive as they move to deliver their FFA?

Answer 5

Apo C-II and Apo E from HDL

Question 6

Name the 5 things that make up the composition of Chylomicrons?

Answer 6

TAGs
CHolesterol
Phospholipids
Apo B48
Apo A

Question 7

About what percentage of TAGs in Chylomicrons are delivered to the peripheral tissues and liver?

Answer 7

80% to muscle, heart and adipose

20% to liver

Question 8

Composition of Chylomicron Remnant

Answer 8

TAGs (90% removed so very little)
Cholesterol
Phospholipids
Apo B48
Apo A

Question 9

Is there a difference between the TAGs in Chylomicrons and VLDL?

Answer 9

Chylomicrons contain dietary TAGs

VLDL contains TAGs synthesized from the liver from carbs

Question 10

Composition of VLDL

Answer 10

Synthesized TAGs (from liver)
Cholesterol
Phospholipids
ApoB-100
ApoC-1
ApoC-3

Question 11

Function of Apo C-II

Answer 11

To activate lipoprotein lipase and release FA from TAGs to adipose and muscle.

Question 12

Does IDL contain Apo C-II and Apo E

Answer 12

Yes, it has not released them yet

Question 13

Composition of LDL

Answer 13

Apo B-100
Cholesterol
Cholesterol Ester
Phospholipids

Question 14

Function of Apo B-100

Answer 14

To be used as a ligand to recognize LDL receptors on the liver

Question 15

What type of fats block LDL receptors on the liver and prevent LDL from being endocytosed?

Answer 15

Saturated fats

Question 16

What happens when LDL returns to the liver and returns the cholesterol? What enzyme is affected?

Answer 16

There is an oversupply of cholesterol in the liver.

HMG CoA Reductase is down regulated and turns off cholesterol synthesis. This also down regulates LDL Receptor synthesis

Question 17

What is the effect of Saturated fats blocking LDL receptors

Answer 17

Increased Cholesterol serum levels

Increases Cholesterol synthesis because HMG CoA Reductase is active with the small amount of cholesterol in the liver

Question 18

Function of Apo E

Answer 18

Used on Chylomicrons to bind to liver receptors to become enocytosed

Question 19

What plays a role as a reservoir for Apo C-II and Apo E

Answer 19

HDL