Biology

Difference Between Apoptosis and Necrosis

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Main Difference

The main difference between Apoptosis and Necrosis is that Apoptosis is the cell death in which the cell abolishes itself for keeping a normal functioning in the body, whereas Necrosis is the accidental death of a cell because of some uncontrolled factors occurring outside the cell environment.

Apoptosis vs. Necrosis

Apoptosis is referred to as the ‘predefined’ death of a cell, whereas Necrosis is referred to as the ‘premature’ death of a cell. The process of Apoptosis takes place through the shrinking of the cell cytoplasm, which follows by the reduction of the cell nucleus; on the other hand, the process of Necrosis takes place by the swelling of the cell cytoplasm with mitochondria which follow by cell lysis.

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Apoptosis is considered as the naturally occurring biological process; on the contrary, Necrosis is considered as the uncontrolled process, caused by some external factors such as trauma, infections, and toxins. In Apoptosis, the irregular bulging of the plasma membrane takes place without losing its uprightness while the integrity of the plasma membrane released in Necrosis.

During Apoptosis, the aggregation of chromatin occurs; on the flip side, no change in the shape of chromatin is observed during the process of Necrosis. The organelles present in the apoptotic cell during Apoptosis remain functional even after the death of the cell, but mitochondria become leaky due to the formation of pores in its membrane, whereas the organelles in the necrotic cell during Necrosis do not remain functional after the death of a cell.

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During Apoptosis, the integrity of lysosomes remains as it is, but mitochondria become permeable; on the other hand, during Necrosis, the integrity of mitochondria remains the same, but lysosomes become permeable. The apoptotic bodies, which are membrane-bound vesicles, have produced that break the cell into small parts through Apoptosis, whereas no vesicles are formed during Necrosis.

Comparison Chart

ApoptosisNecrosis
A natural process of cell death that takes place in the body in which cell itself participate in death is known as Apoptosis.A process of cellular death that occurs accidentally when the cells are opened into the dangerous exterior situations is called Necrosis.
Referred to As
Referred to as the ‘predefined’ death of a cellReferred to as the ‘premature’ death of a cell
Process
The process takes place through the shrinking of the cell cytoplasm, which follows by the reduction of the cell nucleus.The process takes place by the swelling of the cell cytoplasm with mitochondria which follow by cell lysis.
Cause
The naturally occurring biological processThe uncontrolled process, caused by some external factors such as trauma, infections, and toxins
Membrane Integrity
The irregular bulging of the plasma membrane takes place without losing its uprightness.The integrity of the plasma membrane is undone.
Chromatin
The aggregation of chromatin occurs.No change in the shape of chromatin is observed.
Organelles
The organelles present in the apoptotic cell remain functional even after the death of the cell, but mitochondria become leaky due to the formation of pores in its membrane.The organelles in the necrotic cell do not remain functional after the death of a cell because they are disintegrated through swelling.
Mitochondria and Lysosomes
The integrity of lysosomes remains as it is, but mitochondria become permeable.The integrity of mitochondria remains the same, but lysosomes become permeable.
Vesicle Formation
The apoptotic bodies, which are membrane-bound vesicles, are produced that pieces the cell into small parts.No vesicles are formed, but thorough lysis of cell occurs, and the cell contents are spread into the extracellular fluid.
Regulation
Regulated by its initiation of the passageway through enzymesAn unregulated process
Caspase
The pathway depends on the caspase.The pathway does not depend on the caspase.
Energy Requirement
It requires energy because it is an active process.Do no require energy because it is an inactive process.
The Occurrence at 4 °C
Does not take place at 4 °C because it is an active processTakes place at 4 °C
Releasing Factors into Cytoplasm
Many factors, such as AIF and cytochrome C, are released into the suiciding cell cytoplasm through its mitochondria.No material is released into the dying cell cytoplasm.
Occurrence
Involves breakdown of a single cell because it’s a confined processDestroy adjacent group of cells

What is Apoptosis?

The programmed cell death (PCD) or Predefined, a consistent and organized process for the development and the growth of the organism is known as Apoptosis. Apoptosis is sometimes also known as Cellular Suicide because the cell itself participates in death.

The main reason for Apoptosis is that it maintains a balance in cell multiplication, which means that every cell present inside the body contains a self-life. The prominent example is the red blood cells, which live their lives only for 120 days, and then abolishes themselves in the body through Apoptosis.

The well-defined and many following morphological variations start the process of Apoptosis. In Apoptosis, the cell first shrinks through drying, then condenses and finally divides into parts. The aggregation of chromatin inside the nucleus also takes place during Apoptosis.

What is Necrosis?

Another kind of cell death, which also takes place inside the cell because of their high contact with the dangerous outside circumstances, which is different from the typical situations, is known as Necrosis. The dangerous outside conditions can cause harm to the internal environment of the cell, accompanied by fast tissue and cell death.

Therefore, Necrosis is categorized as the accidental, inactive death of the cell. During the process of Necrosis, the cell contents are released into the extracellular environment forming the harmful effects on the adjacent cells. The six morphologically different types of Necrosis are Liquefactive Necrosis, Caseous Necrosis, Coagulative Necrosis, Gangrenous Necrosis, Fibrinoid Necrosis, and Fat Necrosis.

Various factors such as damage in blood vessels, ischemia, mechanical trauma, thermal effects which include tremendously low and high temperatures, and sometimes spider bites cause Necrosis. Necrosis shows severe symptom like inflammation or as well as cause harm to the adjacent cells.

Key Differences

  1. Apoptosis is known as the predefined death of cells that takes place in the body at regular intervals; on the other hand, Necrosis is known as the premature or accidental death of the cell that may take place in the body due to many external factors.
  2. Apoptosis is considered as the naturally occurring death of the cell because it is controlled genetically; on the contrary, Necrosis is considered as pathological because it is not controlled by genes.
  3. Treatment is usually not required in Apoptosis because it is naturally occurring death of a cell; on the flip side, medical treatment is necessary for Necrosis because it occurs accidentally or due to some factors.
  4. The process of Apoptosis is necessary and beneficial to the body, whereas Necrosis is dangerous and harmful to the body.
  5. Apoptosis is a self-derived method because it occurs when the cell gives an indication; however, Necrosis happens because of fungi, viruses, or any harmful toxins.
  6. The symptoms of Apoptosis are not visible because they take place inside the body, while Necrosis shows severe symptom like inflammation or as well as cause harm to the adjacent cells.

Conclusion

The above discussion concludes that the Apoptosis is the naturally occurring biological process, while Necrosis is the pathological process.

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Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White