Final answer:
C5 convertase is an enzyme involved in the complement system, formed when C3b joins C3 convertase. It cleaves C5 into two fragments, C5a and C5b. C5a recruits immune cells, while C5b initiates the formation of the membrane attack complex (MAC) to lyse pathogens.
Step-by-step explanation:
C5 convertase is an enzyme involved in the complement system, which is a part of the immune system that helps defend against pathogens. It is formed when one of the fragments from C3, called C3b, joins C3 convertase. Once formed, C5 convertase has the ability to cleave the protein C5 into two fragments, C5a and C5b.
C5a is a potent inflammatory mediator that recruits immune cells to the site of infection, while C5b initiates the formation of the membrane attack complex (MAC). The MAC is a group of proteins, including C6, C7, C8, and C9, that create pores in the pathogen's plasma membrane, leading to its lysis.