Final answer:
In the presence of survival factors, the activity of the pro-apoptotic protein Bax is inhibited, preventing the initiation of the molecular cascade required for apoptosis and thereby contributing to cell survival.
Step-by-step explanation:
If a survival factor is present in a cell, the pro-apoptotic activity of Bax proteins is usually inhibited. Survival factors can activate pathways that promote the transcription of anti-apoptotic genes like Bcl-2, which block the apoptotic function of Bax. When Bax is inactive, it does not contribute to the formation of mitochondrial membrane channels that release cytochrome c into the cytoplasm, a critical step in the apoptotic process. Without the release of cytochrome c, the cascade of molecular events leading to cell death is not initiated, and the cell survives and continues to function.
This mechanism is essential for maintaining healthy tissues and removing unnecessary or damaged cells. However, if the balance is tipped and survival factors overly suppress Bax, this may contribute to the survival of malfunctioning or damaged cells, as is often observed in cancer.