Apoptosis
Apoptosis is a form of programmed cell death in which a cell dismantles itself in ordered steps: the membrane blebs, the DNA fragments, and the cell breaks into membrane-enclosed pieces that neighboring cells and phagocytes clear without inflammation.
Two pathways in, one executioner
Both entry routes converge on caspase-3, the protease that dismantles the cell.
- Intrinsic (mitochondrial) pathway. Internal stress — DNA damage, oncogene activation, growth-factor withdrawal — activates BH3-only proteins that neutralize the anti-apoptotic BCL-2 family members. The pore-formers BAX and BAK then permeabilize the mitochondrial outer membrane, cytochrome c escapes, and APAF1 assembles the apoptosome, which activates caspase-9.
- Extrinsic (death receptor) pathway. Ligands such as FASL on a cytotoxic T cell cluster deathLog in with DiscordSupport BrinedewContinue to read the draft.
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