Lipids V Flashcards
Hormone senstive lipase
releases FFAs from adipose tissue during fastying periods.
What effect does insulin have on HSL
inhibits, prevents release of FFAs in well-fed state
What effect does cortisol have on HSL
stimulates
Where do FFAs bind
to hydrophobic pockets on the surface of albumine.
Cylomicrons
distribute dietary lipids through the body via lipoportein lipases on the surface of target cells that cleave TAGs and liberate FFAs from chylomicron
VLDL/IDL/LDL
responsbile for distributing endogenously synthesized lipids to peripheral tissues
HDL
function in reverse cholesterol transport from the peripheral tissues to liver for excretion
How do lipids get in and out of lipoproteins
Dietary fats and cholesterol are absorbed by enterocytes that resyntheisze TAGs and pack them inot chylomicrons for dissttrubtion about the body. Newly synthesized chylomicrons are secreted into the lymphatic system and enter the blood via the thoracic duct. As tehy trael through the body, lipoprotein lipases on target cells cleave TAGs and liberate FFAs. Chylomicrons lose lipids and shrink to remnants
ApoA
activators of LCAT
ApoB
Give lipoprotein shape
ApoC
modulate LPL and its equivalent HTGL in liver
Apo E
bind receptors to allow removal of lipid-depleted remnant particles from circulation
Composition of chylomicron
dietary fat in TAG form
Dietary cholesterol as cholesteryl esters
emphipolar phospholipids and choelsterol to form hydrophilic surface
ApoB48 to maintain shape and bind to receptors
ApoC
ApoE
Fate of mature, cholesteryl ester-loaded HDL particle
full HDL binds to scavenger receptor on the surface of liver cells, transfers its choelsterol-shrinks, and can be used for transport again
Why production of LDL is considered the overflow pathway of lipid metabolism.
If the liver sends out more lipids in VLDL particles than the body can consume, the blood concentration of LDL icnreases
