The classical complement pathway is a pathway that is responsible for activating the complement system within the immune system. This pathway begins with the activation of antibodies IgM and IgG. Protein C3 is created, and after a series of reactions, cleaves the C5 protein. This brings phagocytes to the infected area and sets the stage for the coming together of the membrane attack complex (MAC). This complex targets the cell and creates an opening in the membrane, which leads to cell lysis and death.

Classical Complement Pathway References