Cholesterol esters that enter cells through the receptor-mediated endocytosis of lipoproteins hydrolyzed?

he correct answer is (B) Lysosomes.

Cholesterol esters enter cells through receptor-mediated endocytosis of lipoproteins, specifically low-density lipoprotein (LDL). The process occurs as follows:

1. LDL binds to LDL receptors on the cell surface.
2. The LDL-receptor complex is internalized through endocytosis.
3. The complex is transported to lysosomes, where the cholesterol esters are hydrolyzed by lysosomal acid lipase.
4. Free cholesterol is released and distributed to various cellular compartments.

Here’s why the other options are incorrect:

A. Endoplasmic reticulum: While cholesterol can be transported to the endoplasmic reticulum for various cellular processes, it’s not the primary site for hydrolysis of cholesterol esters from lipoproteins.

C. Plasma membrane receptor: The receptor-mediated endocytosis occurs at the cell surface, but the hydrolysis of cholesterol esters happens in lysosomes, not at the receptor site.

D. Mitochondria: Mitochondria are not directly involved in the hydrolysis of cholesterol esters from lipoproteins.

Lysosomes play a crucial role in cholesterol metabolism, and their dysfunction can lead to various lipid storage disorders.