Complement components are ?
**Core Concept**
The complement system is a part of the innate immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is a complex system of proteins that work together to defend against bacterial infections, viruses, and other foreign substances.
**Why the Correct Answer is Right**
The complement system consists of three pathways: the classical pathway, the alternative pathway, and the lectin pathway. These pathways converge at the formation of C3 convertase, which cleaves C3 into C3a and C3b. C3b then binds to the pathogen, marking it for destruction and also activating the terminal pathway, leading to the formation of the membrane attack complex (MAC). This complex forms pores in the bacterial cell membrane, leading to cell lysis and death.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a correct description of the complement components.
* **Option B:** This option is not a correct description of the complement components.
* **Option D:** This option is not a correct description of the complement components.
**Clinical Pearl / High-Yield Fact**
The complement system plays a crucial role in the defense against bacterial infections, and its dysregulation can lead to autoimmune diseases such as systemic lupus erythematosus (SLE).
**Correct Answer:** C. Complement components are proteins that work together to defend against pathogens.