What occurs after the release of cytochrome c from mitochondria during apoptosis?

What occurs after the release of cytochrome c from mitochondria during apoptosis?

• A. Formation of granulomas
• B. Activation of caspases
• C. Inhibition of protein synthesis
• D. Cellular repair mechanisms

Answer: (B)

The release of cytochrome c from the mitochondria is a crucial step in the intrinsic pathway of apoptosis. Once cytochrome c enters the cytosol, it binds to apoptotic protease-activating factor 1 (Apaf-1), which then facilitates the formation of the apoptosome complex. The formation of this complex is essential for the activation of caspases, a family of cysteine proteases that play a critical role in executing the apoptotic program. Once activated, caspases lead to the cleavage of various cellular substrates, resulting in the characteristic morphological and biochemical changes associated with apoptosis, such as cell shrinkage, chromatin condensation, and DNA fragmentation. The other options do not directly relate to the process triggered by the release of cytochrome c. Granuloma formation is typically associated with chronic inflammation and is not a direct consequence of apoptosis. Inhibition of protein synthesis and cellular repair mechanisms do not specifically follow cytochrome c release; instead, they may occur in other pathological contexts but are not the immediate outcomes of this apoptotic signal. Thus, the activation of caspases is the most relevant and direct consequence of cytochrome c release during the apoptotic process.

The release of cytochrome c from the mitochondria is a crucial step in the intrinsic pathway of apoptosis. Once cytochrome c enters the cytosol, it binds to apoptotic protease-activating factor 1 (Apaf-1), which then facilitates the formation of the apoptosome complex. The formation of this complex is essential for the activation of caspases, a family of cysteine proteases that play a critical role in executing the apoptotic program. Once activated, caspases lead to the cleavage of various cellular substrates, resulting in the characteristic morphological and biochemical changes associated with apoptosis, such as cell shrinkage, chromatin condensation, and DNA fragmentation.

The other options do not directly relate to the process triggered by the release of cytochrome c. Granuloma formation is typically associated with chronic inflammation and is not a direct consequence of apoptosis. Inhibition of protein synthesis and cellular repair mechanisms do not specifically follow cytochrome c release; instead, they may occur in other pathological contexts but are not the immediate outcomes of this apoptotic signal. Thus, the activation of caspases is the most relevant and direct consequence of cytochrome c release during the apoptotic process.