Final answer:
When the mitochondria is damaged, cytochrome C leaks out and triggers apoptosis through the intrinsic pathway.
Step-by-step explanation:
If the mitochondria is damaged, cytochrome C leaks out, which triggers apoptosis through the intrinsic pathway. Cytochrome C is a peripheral membrane protein that exists in equilibrium between membrane-bound and unbound states. When it exits the intermembrane space, it binds to adaptor proteins and forms a complex with procaspase, which leads to the release of active caspases. Caspases are proteolytic enzymes that initiate the process of cellular self-destruction.