Mechanism of apoptosis

 Apoptosis occur by extrinsic pathway and intrinsic pathway and both followed by final common pathway.

🍎 apoptosis results from the activation of enzyme called caspases.

Extrinsic pathway (death receptor pathway):-

 1. Fas /CD95or TNF-R ( tumor Necrosis factor receptor) are present in plasma membrane and has death domain.

 2. Fas- ligand (death inducer ) bind to TNF-R .

 3. When FasL bind to Fas , three or more Molecules of Fas are brought together . And their deaths domain form a binding sites for FADD ( Fas-associated death domain) .

 4. Once FADD is attached , it activate initiator caspases pro-caspase 8 (pro -caspase 10) to active caspases 8 .

 5. These initiator caspases activate executioner caspases .

 6. These executioner caspases digest cytoskeleton of cytoplasm, supporting protein for nucleus ,

 And activate DNAses which helps in DNA degradation.

 7. The remaining mass forms Apoptotic bodies , which is engulf by macrophages.