What are the types of endocytosis?

Answer 1

Endocytosis literally means "in - cell - process" (endo - cyt - osis). And that is just what it is: a process for taking materials into a cell by engulfing them.

The cytoskeleton just below the cell membrane forms a part of the cell surface into a cup shape, and the bottom of the cup deepens while the lip of the cup closes all round, until a more or less spherical "bubble" of membrane, a vesicle or vacuole, is pinched off and moves deeper into the cytoplasm.

There are two types of endocytosis:

pinocytosis (derived from a Greek word for "drinking"), in which a relatively small drop of liquid is taken in by the cell;

phagocytosis (from Greek for "eating"), in which something solid is included in the "mouthful".

Pinocytosis happens in every cell, and goes on all the time. Receptor-mediated pinocytosis is a particularly efficient form of pinocytosis. A receptor on the surface of the cell binds to a molecule in the tissue fluid, and the complex of binding molecule (ligand) and receptor is ingested. For example, this is how human cells take in the element iron, which is present in the tissue fluid bound to a protein called transferrin.

Vesicles formed in endocytosis are coated with the protein clathrin. For more details of the role and recruitment of clathrin see the links below. Phagocytosis includes the ingestion of bacteria by phagocytes, one type of human white blood cell involved in defense against organisms that cause disease. Once inside the phagocyte, the bacteria are destroyed.

Answer 2

Three types of endocytosis are as follows : 1) Phagocytosis 2) Pinocytosis 3) Receptor mediated endocytosis