Final answer:
When a membrane is punctured, if it occurs via the immune response through the membrane attack complex, the invading cell can burst due to water intake and osmotic pressure. In other cases, eukaryotic cells may also swell and burst if the swelling exceeds the membrane's ability to expand. The plasma membrane's fluid mosaic nature allows it to self-heal from small punctures.
Step-by-step explanation:
When a small hole is punctured into a membrane, creating free edges, various outcomes can occur depending on the context. In the immune response, the formation of the membrane attack complex following the joining of complement fragments C5, C6, C7, C8, and C9 results in the creation of a hole in the plasma membrane of an invading pathogen. This leads to water rushing into the pathogen's hyperosmotic cytoplasm, causing the cell to swell and eventually burst or lyse, due to osmotic pressure.
However, in the case of eukaryotic cells such as red blood cells, if there's a puncture or when osmotic disruption occurs, the cell may swell. If the swelling is beyond the plasma membrane’s capacity to expand, the cell will likely lyse due to the excessive stress on the membrane. The fluid mosaic model of the plasma membrane explains that it has some flexibility and can self-heal from small punctures due to its composition of lipids and proteins, which allow for a certain degree of movement and resealing after penetration by very fine objects.