Question

Phagocytic cells ingest and sequester pathogens into a structure called a “phagolysosome” which contains singlet oxygen and superoxide radicals (among other molecules). Explain how this immune system strategy works against pathogens. What type of bacteria would you expect to be most vulnerable?

Answer 1

What are pathgens?

Patogens are biological agents that cause disease to its host. They can be virus,bacteria,fungi or parasite.

How does the immune system works against pathogens?

Phagolysosome is formed during the process of phagocytosis. I am explaining the process in the steps below

1. The virus and the cell comes in contact with each other.
2. The cell and the virus binds.
3. Then the macrophage starts to surround the virus and engulfs it into the cell.
4. Phagosome is formed within the cytoplasm.
5. Now here comes the step that you're talking about i.e. the phagocytic cells ingest and sequester pathogens into a structure called a "phagalysosome".
6. These phagolysosomes lower the pH value of its internal environment due to which it comes acidic. This is the reason that it is able to breakdown the stuff inside itself.. This destroys or nuetrilises the infected cells.

Now, telling about the mechanism of oxygen and superoxide radicals. These radicals are highly reactive molecules that react with other biological molecules. They increase radically in the cell which causes oxidative stress and so destroy the pathogens. This is how the strategy works against pathogens.