The natural process leading to cell death is called apoptosisbut when cell death occurs due to the attack of certain external factors such as bacteria, viruses u mushroomsor any toxicityinjury, injury, leads to necrosis.
Apoptosis is the event self-controlled occurring under favourable physiological conditions and the cell is actively involved in the process. During necrosis, the cell is not able to maintain the homeostasisleading to the influx of water and extracellular ions into the cells, even organelles such as mitochondria swell and cause cell lysis.
Numerous cell death events have been observed in multicellular organisms. This natural phenomenon may be due to internal or external factors. There are many morphological, physiological and biochemical differences in both processes.
Now, in this article, we will discuss the critical points at which these two types of cell death processes vary. We will also consider the factors responsible for apoptosis and necrosis and how they are beneficial or detrimental to a cell death process. organism.
Comparative graph between apoptosis and necrosis.
| BASIS FOR COMPARISON | APOPTOSIS | NECROSIS |
|---|---|---|
| Sense | Apoptosis is the programmed cell death that occurs at regular intervals in the body. | Necrosis is premature cell death that can occur randomly in the body. |
| when it occurs | Occurs at a regular interval of time. | Necrosis is an unregulated event. |
| Reason for occurrence | Apoptosis is genetically controlled and is said to be the natural death of a cell. | Necrosis is not genetically controlled and cell death is pathological (not natural). |
| Treatment | As apoptosis is naturally occurring cell death, no treatment is required. | Necrosis requires treatment as it is not the natural death of a cell. |
| Apoptosis takes place when the cell gives a signal, so it is a self-derived process. | Necrosis occurs due to external viruses, fungi or any other toxin. | |
| Cells shrink at the moment of apoptosis. | Cells swell at the time of necrosis. | |
| The fragmentation of the core and the condensation of chromatin are the signs of apoptosis. | The nucleus becomes disorganised and no chromatin condensation occurs. | |
| As apoptosis is the natural process occurring within the body, there are no physical symptoms. | Necrosis causes severe symptoms, such as inflammation, and can also cause damage to neighbouring tissues and cells. | |
| This process requires ATP (energy), as it is an active process. | This process requires no energy and is a passive process. |
Definition of apoptosis
Apoptosis is the cellular response, commonly referred to as ‘apoptosis’. programmed cell death ‘. It is triggered by numerous biological, chemical and physical factors. The whole process of cell degradation is regulated by the family of the ‘ caspases’. -proteases (proteins), highly activated during apoptosis.
Apoptosis is a energy-dependent mechanism which is completed in a few steps. When the cell is triggered to commit suicide, it immediately sends a signal to proteins known as ‘caspases’. The caspases go into action, the cell shrinks and develops blisters (bubble-like protrusions) on its surface. Cellular components begin to fragment and, in the meantime, caspases also trigger the production of DNAases, the enzymes that will destroy the cell’s DNA. DNA present in the nucleus of a cell.
In a few fractions of time, the cell is converted into smaller pieces, packed into a membrane known as a apoptotic body. In addition, these fragments are cleared by macrophages. Immune cells, which are known to clear the debris through the process of phagocytosis (eating cells).
Why does apoptosis take place inside the body? ? There are several reasons for apoptosis to occur, firstly, if the organism no longer needs the cell, which may be due to maintaining the balance of cell numbers, or it could be due to a certain abnormality detected in the cell.
Apoptosis is the process necessary at the time of a baby’s development, as the fingers and toes join together to form a reticular structure in the uterus. With the help of programmed cell death, the network disappears and provides ten separate fingers and toes. Even throughout life, apoptosis functions continuously according to requirements and growth and to keep the body healthy.
Definition of necrosis
The unnatural or unplanned death of a cell is known as necrosis. The reason for this can be infection, toxicity, injury or attack by fungi, viruses or bacteria. It is also said that necrosis may also occur due to hypoxia, which occurs due to inadequate supply of oxygen to nearby tissues.
Necrosis is initiated, as the cell is unable to maintain homeostasis, so extracellular ions and water enter the cell, and cell organelles rupture and ultimately cause the cell to burst due to the osmotic pressure.
Key differences between apoptosis and necrosis.
The following are the essential points that highlight the differences between the two types of cell death, which are apoptosis and necrosis:
- Apoptosis is the programmed cell death which occurs naturally and at regular intervals in the body. Necrosis is premature and unnatural cell death that can occur randomly in the body.
- Apoptosis is genetically controlled, and is said to be the natural death of a cell caused by the cell itself, but necrosis is not genetically controlled and cell death is pathological (unnatural).
- Apoptosis is naturally occurring cell death, so it does not need any treatment, although necrosis requires treatment as it is not the natural death of a cell.
- Apoptosis is always beneficial to an organism’s body, whereas necrosis is harmful to an organism’s body, as it can be fatal and sometimes leads to cancer.
- Apoptosis is the self-derived process of a cell, whereas necrosis is caused by bacteria, viruses, fungi or any external toxin.
- Cells shrink at the time of apoptosis, while cells swell at the time of necrosis.
- Fragmentation of the nucleus and chromatin condensation are the signs of apoptosis, but in necrosis the nucleus is disorganised and chromatin condensation does not occur, the organelles burst, rather than fragment.
- As apoptosis is the natural process that occurs within the body, there are no physical symptoms. Necrosis, on the other hand, causes severe symptoms, such as inflammation, and can also cause damage to neighbouring tissues and cells.
- Apoptosis is a energy-dependent process which requires ATP (energy), as it is an active process. Necrosis is an energy-independent process and is a passive process.
Similarities
- Apoptosis and necrosis lead to the death of a cell.
- This process occurs in plants and animals, although the mechanism is different.
- Apoptosis and necrosis do not occur in prokaryotes.
- In both processes, DNA is fragmented.
Conclusion
There are mainly two types of cell death, Apoptosis and Necrosis, the former naturally and self-induced by the cell, while the latter is triggered by certain external factors such as an attack by virus, bacteria or any toxicity. Ultimately, then, these processes lead to cell death, but they differ in the degradation process and the effect following cell destruction.