Complement system is made about 30 proteins which are circulating in the blood plasma.
These proteins are produced by the liver and my monocytes.
Most of them are inactive. They are cleaved by a protease then converted into an active protease.
In order that serve as a substate of a prior component or as an enzyme to activate a subsequent component.
So, sequential activation produces an expanding cascada activity.
They provide an effector mechanism to enhance the specific antibody-antigen interactions. Antibodies play the role of “finger” the target, on the contrary, a complement destroys it.