Question

Which apoprotein is needed for the release of VLDL from the liver into the blood? Which two apoproteins are needed for the uptake of IDL into the liver?

a) Apo C-II; Apo B-48 and Apo E
b) Apo B-100; Apo C-II and Apo E
c) Apo E; Apo A-I and Apo B-48
d) Apo A-I; Apo C-II and Apo B-100

Answer 1

Apo B-100 is needed for the release of VLDL from the liver into the blood, while Apo C-II and Apo E are required for the uptake of IDL into the liver. The correct answer is b) Apo B-100; Apo C-II and Apo E.

Step-by-step explanation:

The apoprotein needed for the release of very low-density lipoproteins (VLDL) from the liver into the blood is apolipoprotein B-100 (Apo B-100). For the uptake of intermediate-density lipoproteins (IDL) into the liver, the required two apoproteins are apolipoprotein C-II (Apo C-II) and apolipoprotein E (Apo E). Thus, the correct option is b) Apo B-100; Apo C-II and Apo E.

Lipoproteins carry lipids such as cholesterol and triglycerides through the bloodstream. LDL is often called "bad cholesterol" due to its association with heart disease, while HDL is considered "good cholesterol" because it helps remove cholesterol from the bloodstream. Exocytosis is a process that includes the secretion of VLDL particles from the liver into the bloodstream.

Each lipoprotein particle contains various apolipoproteins which play crucial roles in these transport and uptake processes, with Apo B-100 being an essential component for the secretion of VLDL, and both Apo C-II and Apo E being crucial for the hepatic uptake of IDL.