Question

Apoptotic death of a cell may include all of the following except A. Iysis of the cell membrane with inflammation. B. activation of enzymes called caspases. C. phagocytosis. D. binding of a ligand in the extracellular environment to a plasma membrane receptor. E. transfer of toxic molecules from the mitochondria to cytoplasm through protein-induced outer membrane permeabilization.

Short answer

A. Iysis of the cell membrane with inflammation B. Activation of enzymes called caspases C. Phagocytosis D. Binding of a ligand in the extracellular environment to a plasma membrane receptor E. Transfer of toxic molecules from the mitochondria to cytoplasm through protein-induced outer membrane permeabilization Answer: A. Iysis of the cell membrane with inflammation

Step-by-step solution

Recalling apoptosis

Apoptosis is a process of programmed cell death that is essential for the normal development and maintenance of tissues. During apoptosis, cells undergo morphological and biochemical changes, such as chromatin condensation, cell shrinkage, and activation of enzymes known as caspases. This controlled cell death avoids inflammation and influences tissue homeostasis.

Evaluate option A

"Iysis of the cell membrane with inflammation" does not align with the characteristics of apoptotic cell death, as apoptosis is generally a process that avoids inflammation. Instead, this is a process that is seen in necrosis, which is a form of uncontrolled cell death.

Evaluate option B

"Activation of enzymes called caspases" is a crucial step in the apoptosis process. Caspases are proteolytic enzymes that cleave cellular proteins at specific recognition sites and play an essential role in executing apoptotic cell death.

Evaluate option C

"Phagocytosis" is a process through which dying cells are engulfed and removed by phagocytes. It is one of the steps of apoptotic cell death, as it helps with the removal of the dead cells and maintains tissue homeostasis.

Evaluate option D

"Binding of a ligand in the extracellular environment to a plasma membrane receptor" could be part of the process of apoptosis, as apoptosis can be initiated by the activation of death receptors through the binding of ligands. These membrane receptors may activate intracellular caspases and lead to apoptotic cell death.

Evaluate option E

"Transfer of toxic molecules from the mitochondria to cytoplasm through protein-induced outer membrane permeabilization" is a crucial step in the intrinsic apoptotic pathway. Mitochondria play an essential role during this pathway, and the release of cytochrome c and other pro-apoptotic molecules leads to caspase activation, resulting in apoptotic cell death.

Identify the option that does not belong to apoptosis

After evaluating each option, we can see that option A, "Iysis of the cell membrane with inflammation," does not belong to the process of apoptotic cell death since it is a characteristic of necrosis, an uncontrolled cell death process. The correct answer is A.