apoptosis Essay Examples

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Published: Friday 25th of January 2013

Apoptosis Essay Example

Apoptosis is a biological phenomenon which causes cells to die, sometimes referred to as “cell death”. The word comes from an ancient Greek word which means “falling off”, but this makes it sound almost like it’s something unplanned and unwelcome - the death of cells via Apoptosis is actually completely normal, and is part of any growing organism’s development. Cells can undergo various changes such as nuclear fragmentation, cell shrinkage, chromatin condensation and chromosomal DNA fragmentation under apoptosis. The phenomenon was discovered by a German scientist named Karl Vogt in 1842. Apoptosis is commonly confused with necrosis, a form of traumatic death of the cell resulting from an injury. Unlike necrosis, apoptosis is a regulated process that truly creates advantages for a living organism. Without apoptosis, we wouldn't have things such as separated toes or fingers occurring within the embryonic development in the womb. The initiation of apoptosis comes from either the intrinsic pathway or the extrinsic pathway. Once the process of apoptosis begins, it cannot stop, yet this it is not to be feared. The two activation mechanisms of apoptosis induce cell death within any living organisms. If apoptosis follows the intrinsic pathway, cells destroy themselves because they sense stress, whereas, with the extrinsic pathway, cells destroy themselves because others signal for them to do so. Apoptosis serves as a defense mechanism for the body, getting rid of cells that are mutated, abnormal or misshapen. As a rule of thumb, fighting against abnormal cells isn't only the job of apoptosis. Apoptosis becomes a problem when there isn't enough of it, leading to the formation of tumors and other hideous growths. On the flip side, too much apoptosis creates premature aging and the degeneration of the body which also poses a problem. This has led to a large amount of scientific study since the 1990s on apoptosis because it was clear that a lack of apoptosis is a precursor to numerous cancerous diseases. Many of today's anticancer medicines relate to processes of cell growth regulation, doctors frequently drawing upon the ideas of apoptosis to make these medicines work effectively. In terms of cancerous growths, if a cell becomes infected with a virus or becomes too damaged through either radiation or hazardous chemicals, a cell can “decide” not to die as it’s supposed to. This lack of apoptosis can cause that particular cell to multiply and can also cause neighboring cells around it to multiply rapidly as well. The uncontrollable multiplication of cells from a lack of apoptosis will result in a tumor. There are a number of viruses out there termed oncoviruses that can cause genes to destroy proteins within a cell that are important for apoptosis, therefore causing cancers. If you put it in this context, the idea of cell death becomes something to be embraced rather than despised. As well as cell division and growth, apoptosis is important for strong immune function in the body. Without regulated apoptosis, a wide spectrum of disease can result in the immune system, such as immunodeficiency and autoimmune disease. Mechanisms, which carry out cell death, can have a significant impact on deleting immune cells, cytotoxic killing and recognizing self-antigens. If the immune system is weak, this can lead to rapidly increased or decreased cell death - the tables can turn both ways. Apoptosis plays a large part in body homeostasis. The correct regulation of cells within the body is required in order for a person to survive on a daily timescale. Within a day an average person can grow about 50 billion new cells, a lot of which obviously need to die with apoptosis. One can only imagine what the body would look like if none of these cells were to disintegrate properly - in fact, it is estimated that the body would have twice as many cells in a single year. Living things would seem pretty strange indeed without apoptosis. During the process of necrosis, cells swell up and explode, releasing their contents. Apoptosis causes cells to shrink and divide into different parts, allowing them to become absorbed by surrounding ones or macrophages by the process of phagocytosis. This process can be thought of as cell intake used to remove pathogenic organisms and debris from cells, though small minerals and bacteria can also be consumed. The immune system functioning is based on an ability to remove pathogens and debris from the body through phagocytosis. Apoptosis helps to bring about this removal, and so is crucial for the workings of the immune system. The role of apoptosis is vital in embryonic development and morphogenesis. A great example is the elimination of body material when fingers are separated. Morphogenetic apoptosis acts to sculpt a large mass of tissue to result in a developing new shape that is made up of a hand with five digits. Without apoptosis, there would be no remodeling and hands would resemble something more like webbed flippers. It is important to note also that programmed cell death via apoptosis also occurs in many plants too, although the process is vastly different to that in animals. There are striking differences, however, mostly related to the fact that plant cells have a cell wall and they also lack an internal immune system that removes dead cell pieces. Instead of immune system functioning, cells that die break themselves down into pieces but aren’t taken up by pathogens. Apoptosis plays a crucial part in the development of plant and animal life. Without it, things would look very different than they do today. “Cell death” is not as morbid as may appear on the face - the phenomenon of apoptosis enhances living organisms and lets them flourish.