How does phagocytosis differ from endocytosis A All of the c

How does phagocytosis differ from endocytosis?

A. All of the choices are true of phagocytosis and not true of endocytosis.

B. Phagocytosis proceeds by membrane invagination.

C. Phagocytosis uses pseudopods to surround and engulf material.

D. Phagocytosis requires binding to specific membrane receptors.

Solution

Phagocytosis means “cell eating”. Large molecules or particles are internalized through the process of phagocytosis. Only few body cells are able to perform phagocytosis include white blood cells which play an important role in the host defense mechanism. These cells when encounter a large particle like bacterium or cell or tissue debris, external surface projections called pseudopods or false feet, surround the particle, trap and engulf it and internalize in a vesicle called phagosome.

Receptor-mediated endocytosis is highly selective process through which the cells import specific large molecules when they are required by the cellular environment. The process is triggered by binding of a specific protein or molecule to a surface receptor on the membrane. The binding results in formation of a pocket in the plasma membrane and squeezing it inside the cell forming a seal at the surface.

The membrane deforming coat proteins occurring on the inside of the plasma membrane form the buds and are known as the coated pit because they are coated with clathrin. The infectious agents such as flu virus and human immunodeficiency virus (HIV) gain entry into host body through the process receptor-mediated endocytosis.

Therefore, option C is correct.