Which mechanism is listed in the material as part of apoptosis?

• A. Activation of lysosomes to rupture spontaneously
• B. Activation of autophagy only
• C. Leaky or popping lysosomes
• D. Necrosis due to ATP depletion

Answer: (C)

Lysosomal membrane permeabilization, where lysosomes become leaky, can contribute to apoptosis by releasing enzymes like cathepsins into the cytosol. These enzymes help activate the caspase cascade or modulate Bcl-2 family proteins, tipping the cell toward programmed death in a controlled way. Full lysosome rupture would tend to cause uncontrolled cell damage and necrosis, while autophagy is a separate degradation pathway that can promote survival or autophagic cell death, not the main apoptotic route. Necrosis due to ATP depletion is energy-failure death, not the orderly, caspase-driven process of apoptosis. So leaky lysosomes fit as a mechanism listed for apoptosis because they provide a controlled enzymatic trigger that amplifies apoptotic signaling.