Lipoprotein structure

Question 1

What are the functions of lipoprotein

Answer 1

It transports cholesterol and lipids from the blood or from the tissues of absorption to the tissues of storage.

Question 2

Abnormalities that result when the lipoproteins do not function right

Answer 2

1. Diabetes 2. Obesity 3. Atherosclerosis

Question 3

What is the structure of lipoproteins

Answer 3

They have a charged outer core and a neutral inner core to carry lipids and cholestrol in blood. The big orange region on the surface is the apolipoprotein that is responsible for transmembrane transport or activating an enzyme

Question 4

What are the different kinds of lipoproteins

Answer 4

There are

1. HDL: smallest, carry the least amount of lipids thats why they are high density
2. LDL: medium in size, carry more lipids than HDL
3. VLDL: intermediate between LDL and chylomicrons
4. Chylomicrons: very large, largest as a matter of fact, carry a lot of lipids, lowest density

Question 5

What is different about HDL and all other lipoproteins

Answer 5

HDL is the smallest and it doesnt have appo-B lipoprotein

Question 6

What is unique about chylomicrons

Answer 6

Largest of the lipoproteins, they contain B containing alipoprotein called the B-48. All the rest of the lipoproteins have B-100 (except for HDL which doesnt have any)

Question 7

What is the significance of B-100 apolioprotein

Answer 7

It is the ligand for LDL receptors

Question 8

Name the major processing proteins associated with lipoproteins and state their functions

Answer 8

1. Lipoprotein lipase (LPL): found in the blood vessels
2. Lecithin:cholestrol acyltransferase (LCAT): it esterifies cholestrol
3. Heaptic triglyceride lipase (HTGL): found in the liver
4. Cholestrol ester transfer protein (CETP): loads cholestrol on the lipoproteins, for example from HDL to VLDL

Question 9

Name the associated receptors and receptor proteins of lipoproteins

Answer 9

1. LDL receptor: found in liver
2. LDL related receptor proteins: found in many tissues
3. Scavenger receptor (SR-A is found on macrophages and SR-B is found on hapatocytes that mediates the uptake of LDL)
4. Cholestrol/phospholipids transport proteins