NME 2.14 Flashcards
what are the two distinct pathways for lipoproteins transport?
- exogenous
- endogenous
what is exogenous pathway?
from food to tissue
what is endogenous pathway?
syntehsised in liver to tissue
explain exogenous pathway?
- 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
explain endogenous pathway
- 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
which lipoprotein are cholesterol rich?
- HDL
- LDL
which lipoprotein are intermediate?
- IDL
- Chylomicrons remnants
which lipoprotein are triglyceride rich?
- VLDL
- Chylomicrons
which lipoprotein are involved in exogenous pathway?
- chylomicrons
- chylomicrons remnants
which lipoprotein is involved in endogenous pathway?
- LDL
- IDL
- VLDL
which lipoprotein has high phospholipid?
- HDL
- LDL
which lipoprotein has triglyceride?
- VLDL
- chylomicrons
what does apo E do?
- surface of chylomicrons and provide alternate handle for receptors
- this happens when apo B is not in the right confirmation shape
what does cholesterol deposition cause?
atheromatous plaque
what is apo B?
- a major apolipoprotein of VLDL, IDL and LDL