AP BIOLOGY

Detailed explanation-1: -Cytotoxic CD8 T cells carry out their killing function by releasing two types of preformed cytotoxic protein: the granzymes, which seem able to induce apoptosis in any type of target cell, and the pore-forming protein perforin, which punches holes in the target-cell membrane through which the granzymes can enter.

Detailed explanation-2: -Proteolytic cleavage of a limited number of cellular proteins is a central biochemical feature of apoptosis. Aspartate-specific cysteine proteases, the so-called ‘caspases’, are the main enzymes involved in this process.

Detailed explanation-3: -Cytotoxic enzymes appear to be efficient tools to combat cancer. Ideally, one molecule of a protein toxin would be enough to induce the death of a single cell. However, a number of reasons hamper the utilization of cytotoxic enzymes.

Detailed explanation-4: -Perforin released from cytolytic granule binds to target cell membrane and form a pore leading to activation of cell cytotoxicity.

Detailed explanation-5: -A substance that kills cells, including cancer cells. These agents may stop cancer cells from dividing and growing and may cause tumors to shrink in size.