What is the function of the complement component C5?

What is the function of the complement component C5?

• A. Activation of phagocytes
• B. Formation of the membrane attack complex
• C. Stimulating inflammation
• D. Cleaving C3 into C3a and C3b

Answer: (B)

The function of the complement component C5 is primarily related to the formation of the membrane attack complex (MAC). When activated as part of the complement system, C5 is cleaved into C5a and C5b. C5b then interacts with other complement components, particularly C6, C7, C8, and C9, to assemble the MAC, which creates pores in the cell membranes of pathogens. This process leads to cell lysis and is an important means by which the immune system eliminates pathogens. This understanding of C5's role is crucial for grasping how the complement system operates as a component of innate immunity. The activation of phagocytes, stimulating inflammation, and cleaving C3 into C3a and C3b are indeed important functions of other components of the complement system. However, these functions are not directly associated with C5, highlighting its specific role in the ultimate formation of the membrane attack complex.

The function of the complement component C5 is primarily related to the formation of the membrane attack complex (MAC). When activated as part of the complement system, C5 is cleaved into C5a and C5b. C5b then interacts with other complement components, particularly C6, C7, C8, and C9, to assemble the MAC, which creates pores in the cell membranes of pathogens. This process leads to cell lysis and is an important means by which the immune system eliminates pathogens.

This understanding of C5's role is crucial for grasping how the complement system operates as a component of innate immunity. The activation of phagocytes, stimulating inflammation, and cleaving C3 into C3a and C3b are indeed important functions of other components of the complement system. However, these functions are not directly associated with C5, highlighting its specific role in the ultimate formation of the membrane attack complex.