Final answer:
The intrinsic pathway of apoptosis is initiated by the release of cytochrome C from mitochondria, which then binds to adaptor proteins and procaspases to produce active caspases, ultimately leading to the cell's auto-digestion and death. This modulates protein expression, cellular metabolism, and cell growth, integral for organismal health.
Step-by-step explanation:
Intrinsic Pathway Activation of Apoptosis
The intrinsic pathway of activating apoptosis is one of the main mechanisms by which cells can induce self-destruction. This pathway is essential for the development and maintenance of a healthy organism by eliminating damaged or unnecessary cells. The molecule that activates the intrinsic cascade of apoptosis is cytochrome C. When mitochondrial membranes are compromised, cytochrome C is released into the cytosol, wherein it binds to adaptor proteins, leading to the aggregation of the cytochrome c-adaptor complex. This complex, in turn, has a high affinity for procaspases, which are inactive precursors of caspases. Upon binding, an allosteric change occurs in the procaspase molecule, ultimately generating an active caspase. Caspases are key proteolytic enzymes that orchestrate the auto-digestion of the cell. These active caspases are responsible for cleaving various cellular proteins leading to the orderly dismantling of cellular components and cell death.
Signaling pathways, including the intrinsic pathway of apoptosis, direct protein expression, cellular metabolism, and cell growth. Therefore, proper regulation of apoptosis is crucial for the organism's homeostasis.