PATHOLOGY

Detailed explanation-1: -The complement system is made up of a large number of distinct plasma proteins that react with one another to opsonize pathogens and induce a series of inflammatory responses that help to fight infection. A number of complement proteins are proteases that are themselves activated by proteolytic cleavage.

Detailed explanation-2: -The MAC complement proteins form a circular complex that kills the microbe by forming pores in the microbial cell membrane, thereby allowing water and salt ions into the cell.

Detailed explanation-3: -At the basic level the broad functions of the complement system can be split into three areas: (1) the activation of inflammation; (2) the opsonization (labeling) of pathogens and cells for clearance/destruction; (3) the direct killing of target cells/microbes by lysis.

Detailed explanation-4: -So-called complement proteins of the human immune system can kill certain bacteria (Gram-negative bacteria) by creating ring-shaped pores (named the Membrane Attack Complex, MAC) in their cell wall.