Lipoprotein Metabolism Flashcards
rupture of atherosclerotic plaques lead to what
MI
produced from intestine and transports fat (TG’s) to adipose tissue and muscle
Chylomicrons
marker signal for chylomicrons that helps get it out of intestine
B-48
produced from liver and transports fat (TG’s) to adipose tissue and muscle
VLDL
marker signal for VLDL that gets it out of liver
B-100
where can LDL be distributed (3 places)
liver (recycled); skeletal m. (rebuild); arteries (bad fate)
storage form of fat
triglycerides
transports FA’s in the blood
Albumin
____important for membrane fluidity
cholesterol
major component of cell membranes and major dietary source of energy
lipids
nonpolar lipids (no H+ bonding)
TG’s
cholesterol ester
polar lipids (some H+ bonding); move b/t particles
FA’s
phospholipids
cholesterol
worst type of fatty acid; in processed foods
trans fatty acid (cis double bond)
mixture of polar and nonpolar FA’s w/ fat in the core
micelle
flip membrane and get cholesterol to HDL
ABCAs
break bonds and get nonpolar lipids out and broken down to FA’s at site of liver
lipase
reintroduces ester bonds and resynthesize TG’s
acyltransferase
2 main sources of cholesterol
diet, liver
what happens when our body (macrophages) cannot break down cholesterol
foam cell
statins block this and prevent cholesterol synthesis
HMG-CoA Reductase
movement of lipids in the blood through what
lipoproteins
binds lipids and takes them where they need to go
apoproteins
transports excess cholesterol to cells that may need it
LDL
activates LDL (lipase)
C2/A5 apoproteins
directs lipids into cells that need them and back into liver for recycling; high affinity ligand for LDLR
E3 apoprotein
apoprotein that prevents removal of TG rich proteins into liver and keeps it in blood longer
C3
apoprotein that activates hepatic lipase
A2
% of fat we eat that gets stored
98%
how fat moves through body: 4 main steps
- start in lumen of gut; goes to intestinal epithelial cells
- fat into FA’s then to TG’s
- TG’s to chylomicron and leaves
- goes to lymphatic system and then to subclavian veins
role of MTP
TG’s to chylomicrons/VLDL
gets fat into micelles
bile salts
how plant sterols are taken out of blood
ABCG5/ABCG8
what happens if you don’t have MTP
abetalipoproteinemia
how chylomicrons bind target tissue
w/ C5/A5 and GPIHBP1
occurs in fed state (how lipids are stored in adipocytes)
insulin brings glucose in (GLUT-4 transporter)
glycerol backbone for TG’s
remnants of lipids 2 fates in the liver
recycled or degraded by lysosomes
prevents recycling of LDLR to membrane of liver cells
PCSK9
what happens in liver when there is too much cholesterol (3 things)
- ACAT turns it into cholesterol ester
- liver turns it into VLDL and kicks it out
- downregulate LDLR
in refeeding state, liver will do what to TG’s
turn it into glucose
in refeeding state, liver will do what to FA’s
turn it into ketone bodies
in refeeding state, liver will do what to cholesterol
turn into bile salts and then bile in gallbladder
healthy liver does not _____fat; kicks it out as____
store; VLDL
what happens when there is excess of calories or cholesterol and liver can’t break it down to VLDL
accumulation of fat; fatty liver
if ____bound to LDL doesn’t bind to LDLR on liver what happens
B100; last up to a week in blood and accumulate in arteries
