NME 2.14 Flashcards
1
Q
what are the two distinct pathways for lipoproteins transport?
A
- exogenous
- endogenous
2
Q
what is exogenous pathway?
A
from food to tissue
3
Q
what is endogenous pathway?
A
syntehsised in liver to tissue
4
Q
explain exogenous pathway?
A
- bile emulsify fats
- lipase cleaves triacyglycerol into two fatty acid and one-2-monoacylglycerol
- enterocytes absorb small molecules and form triacylglycerides
- nascent chylomicrons circulate through lymphatic vessels
- nascent chylomicrons interact with HDL particles cause donation of apolipoprotein C-II and apolipoprotein E
- chylomicrons is now matured
- through apolipoprotein C-II mature chylomicrons activate lipoprotein lipase
- LDL helps with hydrolysis of triacylglycerol
- glycerol and fatty acids can then be absorbed in peripheral tissues
- hydrolused chylomicrons are called chylomicrons remnants
- chylomicrons remnants continue in circulation until interact with chylomicrons remnant receptors through apolipoprotein E
- cause hydrolysis and release glycerol and fatty acid
5
Q
explain endogenous pathway
A
- hepatocytes create triacylglycerols through de novo synthesis
- produce bile from cholesterol
- triacylglycerols and cholesteryl ester are assembled with apolipoprotein B-100 to form nascent VLDL
- nascent VLDL release into blood
- VLDL bump with HDL
- HDL donate apolipoprotein C-II and apolipoprotein E to nascent VLDL
- nascent VLDL is considered matured
- apolipoprotein C-II activate LPL
- LPL hydrolyze VLDL and release glycerol and fatty acids
- hydrolyzed particles are called VLDL remnants or IDL
- IDL circulate and interact with apolipoprotein E and remnant receptors to be absorbed in the liver
can be further hydrolysed by hepatic lipase - LDL circulate and transport free cholesterol
- LDL can bind with LDL receptors and apolipoprotein B-100
- LDL is internalised and hydrolysed
6
Q
which lipoprotein are cholesterol rich?
A
- HDL
- LDL
7
Q
which lipoprotein are intermediate?
A
- IDL
- Chylomicrons remnants
8
Q
which lipoprotein are triglyceride rich?
A
- VLDL
- Chylomicrons
9
Q
which lipoprotein are involved in exogenous pathway?
A
- chylomicrons
- chylomicrons remnants
10
Q
which lipoprotein is involved in endogenous pathway?
A
- LDL
- IDL
- VLDL
11
Q
which lipoprotein has high phospholipid?
A
- HDL
- LDL
12
Q
which lipoprotein has triglyceride?
A
- VLDL
- chylomicrons
13
Q
what does apo E do?
A
- surface of chylomicrons and provide alternate handle for receptors
- this happens when apo B is not in the right confirmation shape
14
Q
what does cholesterol deposition cause?
A
atheromatous plaque
15
Q
what is apo B?
A
- a major apolipoprotein of VLDL, IDL and LDL
