What is Receptor mediated endocytosis is by and explain in detail?
Ans is A i.e. Clathrin EndocytosisThe process by which cells take up large molecules is called endocytosis.Endocytotic vesicles are generated when segments of the plasma membrane invaginate, enclosing a minute volume of extracellular fluid and its contents. The vesicle then pinches off as the fusion of plasma membranes seals the neck of the vesicle at the original site of invagination.* There are two general types of endocytosis:PhagocytosisPinocytosisPha2ocvtosisinvolves ingestion of large particles such as viruses, bacteria, cells or debris.Phagocytosis occurs only in specialized cells such as macrophages and granulocytes.PinocytosisIt is a property of all cellsIt is cellular uptake of fluid and fluid contents.Pinocytosis is of two types :Fluid phase pinocytosis - is a non-selective process in which the uptake of a solute is simply proportionate to its concentration in the surrounding extracellular fluid:Absorptive pinocytosis: is a receptor mediated selective process primarily responsible for the uptake of macromolecules. The vesicles formed during absorptive pinocytosis are derived from invagination (pits) that are coated on the cytoplasmic side with a filamentous material. In many systems, clathrin is the filamentous material. For .e.g LDL is internalized by means of coated pits containing the LDL receptors.