Final answer:
The word describing the killing of a damaged cell is called programmed cell death or apoptosis. It is a biological process that allows controlled cellular death and is essential for the maintenance of cellular health and immune response, often involving the action of killer T cells.
Step-by-step explanation:
When discussing a damaged cell that is subsequently killed, the process is known as programmed cell death or apoptosis. This biological mechanism enables a cell to die in a controlled way that avoids harm to the organism by releasing potentially damaging molecules. It's a critical aspect of the immune response, particularly in the context of killer T cells (cytotoxic T cells), which play a role in destroying cells infected by viruses or that have become cancerous.
During an immune response, killer T cells attach to and spread over a target cell, such as a cancer cell or a virus-infected cell, delivering chemicals that cause the target cell to undergo apoptosis, a process sometimes referred to as 'the kiss of death'. These events are essential for maintaining cellular homeostasis and protecting the organism from damaged or harmful cells.
Another event that initiates apoptosis involves the disruption of cellular receptors with the extracellular matrix leading to a cascade that causes the cell to self-destruct. This mechanism prevents cells from proliferating uncontrollably, as seen in metastatic tumor cells. Should the internal regulation of a cell fail, due to a condition like uncontrolled division or viral infection, these external mechanisms can still guide cells towards apoptosis to prevent further damage.