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How can your immune system punch holes in bacteria?

Some immune proteins assemble into a structure that can damage a bacterium's membrane. This membrane attack complex belongs to the complement system, one part of the body's defenses. Explore how forming a pore differs from swallowing a target, and why bacterial membranes are not equally vulnerable.

3–5 min

Questions you could explore

  • Why does the same protein assembly affect some bacterial targets more than others?
  • How does forming a pore differ from an immune cell engulfing a target?

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  • OpenStax17.2 Chemical Defenses

    Explains the protein cascade, pore formation and why bacterial structure affects susceptibility. Complement also has other roles, so this mechanism is only part of the system.

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