Question

A bacterial cell has been tagged by antibodies and is destined to undergo phagocytosis. Discuss the process of phagocytosis and the steps involved. Make sure to discuss in your answer lysosomes, digestion and phagolysosomes.

Answer 1

The process in which living cells (phagocytes) engulf other cells or particles is called Phagocytosis. Phagocytes are type of cells that has the ability to ingest and digest, foreign particles. It can engulf the foreign bodies by extending its cytoplasm into pseudopods. It surrounds the foreign particle and form a vacuole. phagocyte enzymes are In this vacuole enzymes are secreted by which digestion takes place. The two types of white blood cells i.e neutrophilic leukocytes and monocytes are phagocytic in nature. Neutrophils are small while monocytes are large in size. White blood cells can phagocytosed bacteria, dead tissue cells, various dust particles, pigments and other minute foreign bodies. Mostly macrophages are found in the lungs, liver, spleen, and lymph nodes. Their main role is to free up the airways, blood, and lymph of bacteria and other particles. While Neutrophils can be carried by the circulating blood until they reach an infected tissue. Through this tissue it passes through the blood vessel wall and set in that tissue.

Depending on the size of the particle, the speed with which a phagocytic cell ingests varies. The engulfed objects are enclosed within a membrane-bound vacuole called a phagosome. With the help of hydrolytic enzymes, the ingested particle are digested by phagocyte. These enzymes are found in cell with membrane enclosed sacs called as lysosomes. Digestion takes place in the vacuole where enzymes are secreted.