Final answer:
Receptor-mediated endocytosis is a cellular mechanism where specific molecules, such as LDL cholesterol, are internalized into the cell via clathrin-coated vesicles after binding to cell surface receptors. This process is crucial for the regulation of substances within the body, and its dysfunction can lead to diseases like familial hypercholesterolemia.
Step-by-step explanation:
Definition and Function of Receptor-mediated Endocytosis
Receptor-mediated endocytosis is a cellular process where cells absorb molecules by the inward budding of the plasma membrane. This process is initiated when specific molecules outside of the cell, known as ligands, bind to cell surface receptors. The cell membrane then invaginates, forming a clathrin-coated vesicle that encapsulates the substance for internalization.
The primary function of this process is to allow cells to intake specific substances that are present in the extracellular fluid. For instance, LDL cholesterol is typically removed from the blood via receptor-mediated endocytosis. However, when this process is defective, as in the case of familial hypercholesterolemia, harmful levels of cholesterol can accumulate in the blood, leading to serious health issues.