Plasma Lipoproteins

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What happens to apo-Cs during lipoprotein metabolism?

They are transferred to HDLs (correct)

They are converted to LDLs

They are transferred to IDLs

They are broken down into cholesterol

What is the primary function of LDLs in lipoprotein metabolism?

To package cholesterol for storage in adipose tissue

To transport dietary cholesterol from the liver to peripheral tissues (correct)

To synthesize cholesterol de novo within cells

To transport cholesterol from peripheral tissues to the liver

What is the exclusive apolipoprotein of LDLs?

Apo-Cs

Apo-E

Apo-B-48

Apo-B-100 (correct)

What is the primary site of LDL uptake in the body?

Liver Signup and view all the answers

What is the role of LDL receptors in lipoprotein metabolism?

To mediate the uptake of LDLs by cells Signup and view all the answers

What happens to the cholesterol esters in lysosomes after LDL uptake?

They are hydrolyzed to yield free cholesterol Signup and view all the answers

What is the function of ACAT in lipoprotein metabolism?

To re-esterify excess intracellular cholesterol Signup and view all the answers

What happens to the LDL receptor-apo-B-100 complex after LDL uptake?

It is broken down in lysosomes Signup and view all the answers

What is the sole apoprotein present in LDLs?

apo-B-100 Signup and view all the answers

Where are HDLs synthesized?

Liver and small intestine Signup and view all the answers

What is the primary function of HDLs?

To act as circulating stores of apo-C-I, apo-C-II and apo-E Signup and view all the answers

What is the enzyme associated with HDLs that esterifies free cholesterol?

LCAT Signup and view all the answers

What is the result of the action of LCAT on free cholesterol?

Generation of cholesteryl ester and lysolecithin Signup and view all the answers

What is the result of HDLs acquiring cholesterol from macrophages?

Increase in HDL uptake and catabolism by the liver Signup and view all the answers

How do HDLs acquire cholesterol from cells?

By extracting it from cell surface membranes Signup and view all the answers

What is the effect of HDL-mediated cholesterol removal from cell surface membranes?

Decrease in intracellular cholesterol levels Signup and view all the answers

What is the primary function of lipoproteins in the body?

To transport lipids in the blood to reach different tissues Signup and view all the answers

What is the main component of the core of lipoproteins?

Triacylglycerol and cholesterol Signup and view all the answers

What is the classification of lipoproteins based on ultracentrifugation?

Density Signup and view all the answers

What is the main difference between chylomicrons and other lipoproteins?

Origin of formation Signup and view all the answers

What is the primary lipid component of chylomicrons?

Triacylglycerols Signup and view all the answers

What is the function of apo-C-II in chylomicrons?

To activate LPL in the presence of phospholipid Signup and view all the answers

Where do chylomicrons enter the circulation?

Left subclavian vein Signup and view all the answers

What is the origin of chylomicrons?

Intestinal mucosa Signup and view all the answers

Where are free fatty acids (FAs) released from chylomicrons absorbed?

Tissues such as adipose and muscle Signup and view all the answers

What happens to the glycerol backbone of triacylglycerols (TGs) after cleavage by lipoprotein lipase (LPL)?

It's returned to the liver and kidneys for conversion Signup and view all the answers

Which apoprotein is necessary for chylomicron remnants to be recognized by the hepatic remnant receptor?

apo-E Signup and view all the answers

What is primarily transported by Very Low Density Lipoproteins (VLDLs)?

Endogenously derived triacylglycerols to extra-hepatic tissues Signup and view all the answers

How are triacylglycerols delivered to tissues by VLDLs?

Through the action of lipoprotein lipase (LPL) Signup and view all the answers

Which of the following statements is accurate regarding chylomicrons?

They deliver dietary TGs to adipose tissue and muscle Signup and view all the answers

What characteristic changes occur in VLDLs after the action of LPL and loss of certain apoproteins?

They transform into IDLs (VLDL remnants) Signup and view all the answers

What is the main role of nascent chylomicrons in the body?

Deliver dietary TGs and cholesterol to various tissues Signup and view all the answers