Diseases of Lipid Metabolism Flashcards
where is phosphatidylcholine most present?
endoplasmic reticulum
where is sphingomyelin most present?
plasma membrane
where is phosphatidylethanolamine most present?
inner membrane of the mitochondria (lots in outer too)
both phosphatidylserine and phosphatidylinositol are involved in signalling–not abundant in any membranes
ya
where is cardiolipin present?
inner membrane of mito
no phosphatidylcholine in bacteria
ya
what transports TAGs?
chylomicrons and VLDL
what transports cholesterol?
LDL and HDL
as size of the four lipoproteins increases, density decreases
ya
since the lipoproteins have differing densities, they can be separated via centrifugation
ya
Apoprotiens are inexchangeable– once they’re bound to a lipo, they’re bound for good
ya
what lipoproteins is apoB found on?
CM, VLDL, and LDL
where is apoB100 produced and where is it recognized?
produced only in the liver; recognized by LDL receptor in liver and other tissues
what is apoB48, where is it found?
an RNA-edited version of apoB48– 48% similar to apoB100–>editing happens in the intestine; found on chylomicrons
lipid asymmetry exists to help the curvature of the membrane
ya
what is FA synthesis catalyzed by?
FA synthetase
malonyl-CoA is the carbon donor for each round of condensation for FA synth
ya
why are linoleate and a-linoleate essential FAs?
because humans lack 12 and 15 desaturases
what ar FA synth and and ox pathways linked by?
malonyl coa
why do FAs need to be stored as TAGs?
FAs are toxic at high conc in the cell
rule of thumb for FAs
C1- saturated, c2,3=unsat
sites other than adipose tissue for fat storage
liver, small int, mammary glad
what do chylomicrons and VLDL transport?
TAGs
what do LDL and HDL transport?
chol
what apolipoproteins are present on CMs?
B48, C, and E
what apolipoproteins are present on VLDLs?
B100, C, and E
what apolipoproteins are present on LDLs?
B100, C
what apolipoproteins are present on HDLs?
A
what is the role of ApoB 100?
binds to LDL receptor
what is the role of ApoB 48?
chol transport/clearance
what is the role of ApoC2?
activates LPL
which apos are inexchangeable and exchangable?
apo B48 and 100; apo c inex
how can fat be isolated i nteh lab?
adipose tissue+buffer–>homogenize; then, phase separation–> use organic solvent and water–>lipid in organic solvent
