Molecular Fundamentals - Lipoproteins

what gives ApoE and Apo CII to chylomicron in the blood vessels?

HDL

chylomicron has a high level of what?

triglycerides

what breaks triglycerides down in the blood vessels?

lipoprotein lipase

a chylomicron must be tagged with what to be recognized by lipoprotein lipase?

Apo CII

lipoprotein lipase breaks triglycerides down into what?

glycerol and free fatty acids

free fatty acids can go where after being released into the blood vessels?

skeletal/cardiac muscle or adipocytes

what is formed from the part of the chylomicron that didn’t get broken down by lipoprotein lipase?

chylomicron remnant

where does the chylomicron remnant travel to from the bloodstream?

liver

what receptors on the liver recognize the chylomicron remnant?

LDL receptor and heparin sulfate

what does the LDL receptor recognize on the chylomicron remnant?

Apo E

what does the heparin sulfate recognize on the chylomicron remnant?

ApoB 48

Inside the liver, what happens to the chylomicron remnant initially?

• protein degradation to amino acids

• cholesterol to form bile acids, storage, or for membrane

• triglycerides are released

within the liver, what happens to the triglycerides?

go to the rough ER and get packaged by the enzyme MTP to form VLDL

what enzyme converts triglycerides to VLDL?

MTP

MTP converts triglycerides to VLDL and tags it with what?

Apo B100

VLDL has _____ triglycerides and cholesterol than chylomicron.

less

VLDL leaves the liver and travels back where?

to the bloodstream

what tags VLDL with Apo E and Apo CII?

HDL

what is formed from the part of the VLDL that didn’t get broken down by lipoprotein lipase?

VLDL remnant or IDL

VLDL remnant (IDL) can travel where?

• adrenal gland

• liver

• adipocytes

• skeletal/cardiac muscle

cholesterol is used in the adrenal gland to synthesize what?

aldosterone, cortisol, sex hormones

what on the liver recognizes Apo B100?

hepatic triglyceride lipase

after VLDL travels back to the bloodstream, its known was what due to having lower levels of triglycerides and cholesterol?

LDL

LDL can travel where?

• testes

• ovary

• adrenal gland

• liver

LDL travels to the testes to form what?

testosterone

LDL travels to the ovary to form what?

estrogen and progesterone

an increased level of LDL can lead to what?

accumulation of LDL between smooth muscle cells and endothelial cells (oxidized LDL)

accumulation of LDL (oxidized LDL) between smooth muscle cells and endothelial cells can lead to what?

atherosclerosis

what cells try to get rid of the oxidized LDL?

macrophage

what forms when macrophages get overwhelmed by the large amount of oxidized LDL?

foam cells

accumulation of foam cells can lead to what?

atherosclerosis

what lipoprotein takes cholesterol from the foam cells?

HDL

what recgonizes HDL on the liver?

scavenger receptor

scavenger receptor recognizes what on HDL?

Apo A1

what lipoprotein has the most cholesterol and triglycerides, and is the largest?

chylomicron

what lipoprotein has the least amount cholesterol and triglycerides, and is the smallest?

HDL