LIPOPROTEINS - Definition, Classification, Structure & Functions EASY NOTES

DEFINITION

-To become water soluble lipids get complexed with proteins to form lipoproteins

-the protein part of lipoproteins is called as apolipoproteins.

CLASSIFICATION

depending on density of ultracentrifugation or depending on the electrophoretic mobility the lipoproteins are classified into five types

1.Chylomicrons - contain apo B-48

2.Very Low density Lipoproteins(VLDL) - contains apo-B 100

3.Intermediate density lipoprotein

4.Low-Density Lipoprotein(LDL) - contains apo B-100

5.High density lipoprotein(HDL) - contain apo A

STRUCTURE OF LIPOPREOTEIN

-lipoproteins are made up of 

--Polar Periphery - made of proteins

--Polar Head - made of phospholipid & free cholesterol

--Inner Core - made of hydrophobic triglycerides & tail of phospholipids

FUNCTIONS OF LIPOPROTEIN

Functions of Chylomicrons

-Transport of dietary triglycerides from the intestine into adipose tissue from storage

-Transport of dietary triglycerides form intestine to muscle/heart for energy needs

Functions of VLDL

-Transport of endogenous triglycerides from liver to peripheral tissue

Functions of LDL

-Transport of cholesterol from liver to peripheral tissue

Functions of HDL

-Transport of cholesterol from peripheral tissues to the liver so it is excreted through bile, it is called as reverse cholesterol transport by HDL.

-Because HDL helps in the excretion of cholesterol - it is called as anti-atherogenic and is also called as good cholesterol