Complement proteins . a. form pore complexes b. promote inflammation c. neutralize toxins d. a a

Complement proteins . a. form pore complexes b. promote...

Key Concepts

Inflammatory Mediators

Complement proteins also function as inflammatory mediators by generating molecules like C3a and C5a that act as chemoattractants. These molecules trigger the recruitment, activation, and migration of immune cells to sites of infection or damage, thereby amplifying the inflammatory response and contributing to pathogen clearance.

Complement System

The complement system is a crucial component of the innate immune defense, consisting of a series of proteins that circulate in an inactive form and become sequentially activated in response to pathogens or immune complexes. This system aids in opsonization, inflammation, and cell lysis, thereby enhancing the efficiency of the adaptive immune response as well.

Membrane Attack Complex

The membrane attack complex is assembled from complement proteins during the terminal phase of complement activation. It forms transmembrane channels or pores in the target cell membranes of pathogens, leading to cell lysis and death, and is one of the primary mechanisms by which the complement system eliminates bacterial pathogens.

Transcript

00:01 The complement pathway is a complex series of protein activations that is going to help us respond and react to pathogenic organisms and foreign antigens.

00:14 So this complement cascade is a series of nine complement proteins.

00:21 C1 through, we'll say c5, are responsible for simply activating one another in order to act.

00:32 Activate a more important mac complex.

00:37 C6 is also an activating protein, but it is not categorized in that initial c1 through c5 pathway.

00:46 Our c7 through c9 make up that mac complex.

00:51 This mac complex is a pore with a hollow channel that is going to connect itself through the cellular membrane of a pathogenic or reactive cell.

01:07 Because it's hollow, it is going to allow certain solutes and water to flow out of the cell, which is effectually going to eliminate and kill off the cell of interest.

01:21 So when we're considering our answer choices for the functions of complement, we have promotes inflammation, we're going to have the formation of the pore, or the mac complex.

01:42 We have toxin neutralization, and we have both a and b.

01:52 So as i've mentioned, complement is highly involved in making that mac or por complex.

01:58 So for sure, we know that a is a viable answer.

02:01 Now we just need to consider whether b is also a viable option as well.

02:08 Well, since this series of proteins, say c1 through c5, it doesn't make one.

02:14 Much sense why don't we just activate this pathway using a single protein rather than the sequence of proteins...

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