Question

Outcomes of the Membrane Attack Complex

You now know that once complement is activated, all outcomes occur. With respect to the membrane attack complex (MAC), which is most likely to occur once all of the C9 proteins insert into the bacterial plasma membrane?

Answer 1

The membrane attack complex (MAC) leads to the lysis and death of a pathogen by creating a hole in its plasma membrane, causing an osmotic imbalance and resulting in the cell bursting.

Step-by-step explanation:

Once all of the C9 proteins insert into the bacterial plasma membrane to form the membrane attack complex (MAC), the most likely outcome is cell lysis and death of the pathogen. This process occurs when the fragment from C5 joins C6, C7, C8, and C9 to create MAC, which subsequently forms a hole in the pathogen's plasma membrane. As a result, water rushes into the pathogen's hyperosmotic cytoplasm, leading to the pathogen's lysis, or bursting, due to the disruption of its osmotic balance.