Ch5: Endogenous Pathway

Question 1

In general, what is the endogenous pathway?

Answer 1

Lipids synthesized by the liver - transport from the liver to peripheral tissues

Question 2

What lipoproteins are used in the endogenous pathway?

Answer 2

VLDL, IDL, LDL

Question 3

What is step 1 of the endogenous pathway?

Answer 3

Nascent VLDL are made in the golgi apparatus of the liver

Question 4

What is step 2 of the endogenous pathway?

Answer 4

Additional apolipoproteins C and E are transferred from HDL
The fatty acids from TAGs are hydrolyzed by lipoprotein lipase found mainly in muscle and adipose tissue

Question 5

What is step 3 of the endogenous pathway?

Answer 5

As the TAG is removed from the VLDL, the particle becomes smaller and becomes an IDL

Question 6

What is step 4 of the endogenous pathway?

Answer 6

Further loss of TAG and it becomes LDL

Question 7

What is step 5 of the endogenous pathway?

Answer 7

LDL are taken up by LDL receptors found in the liver and non-hepatic tissue
In the liver, LDL is converted into bile acids and secreted into the intestines

Question 8

What is step 6 of the endogenous pathway?

Answer 8

In non-hepatic tissues, LDL is used in hormone production, cell membrane synthesis, or stored
LDL is also taken up by macrophages and other cells which can lead to excess accumulation and the formation of foam cells which are important in plaque formation

Question 9

Review the textbooks overview

Answer 9