The Role of Bcl-2 in Promoting Cell Survival - Term Paper Example

RUNNING HEAD: THE ROLE OF BCL-2IN PROMOTING CELL SURVIVAL Name Student Number Subject The role of Bcl-2 in promoting cell survival 20937 words The role of Bcl-2 in promoting cell survival Table of content 1. Abstract …………………………………………………………………..3 2. Introduction ………………………………………………………………3 3. Cell biology………………………………………………………………..4 4. The structure of a cell……………………………………………………..5 5. Cell organelles …………………………………………………………….6 6. Cell division and lifecycle…………………………………………………7 7. Death of a cell………………………………………………………………7 8. The role of Bcl-2 in promoting cell survival……………………………..8 9. Conclusion…………………………………………………………………10 10. References …………………………………………………………………12 Abstract This report seeks to explain the relationship between Bcl-2 family of proteins and their role in promoting cell survival. The report begin will with a discussion of the cell biology which explains the cell in details by expounding in the cell structure taking in account both plant and animal cells, identifying the cell organelles and highlighting their functions, evaluating the cell cycle and cell division and the death of a cell. The report will also include a discussion of the role of Bcl-2 in promoting cell survival by evaluating situations that prompt apoptosis and the role of Bcl-2 in inhibiting cell destruction by reversing the process. In addition the discussion will identify some negative results that link to the failure of destroying damaged cells. Finally a conclusion consisting of a summary of the main issues in the report will be presented. Introduction The cell is the most important functional unit in an organism and its role is unique to the survival of the organism. Studies show that a cell is too small and the human eye cannot observe it however science and technology has led to the development of devices such as optic/light and the electron microscope which aid the human eye to observe the cell. These devices have magnifying and resolving powers that enable them to enlarge the image of a specimen under observation as well as facilitating the viewing of clear details for instance the electron microscope can display clear images of the plasma membrane. Cell biology is necessary for a clear understanding of the cell and its role in an organism. The survival of a cell is equally important because this is the main determinant of the future of the organism. Therefore whether a cell dies or if live should attract a lot of attention to this study however the cell mechanism is better positioned to decide which cell lives and which one die. Furthermore this processes are genetically instigated to enable the organism adapt to the changing environment and compete effectively therefore it is necessary that the best survive and degenerates are faced out. In addition it is clear that the decision whether a cell should die falls entirely on the cell and in particular the Bcl-2 family of proteins (Khosravi-Far, 2008). Cell suicide is a genetic process inherited from the mother cell to the new cell designed to maintain balance. Whenever a cell experiences intracellular stress for example damage to the DNA the cell becomes a danger and apoptosis begins to facilitate its elimination. However the Bcl-2 group of anti and proapoptotic regulators swing into action and help in deciding whether the cell should die they prevent the process of destroying the cell. On the other hand as the Bcl-2 promotes cell survival some member on the same family facilitates the death of the cell and the development of cancerous cell due to alterations in the cell DNA (Levine, 2009).. Cell biology Living things are made up of millions of small units called cells a name coined by a Robert Hooke an English scientist (M.B.V, 1980) (Books, Cell Biology Literature, 2010). Hooke points that even though cells are extremely small/minute they are functional and contain a lot of information about the main organism he also argue that the cell is the most important unit in a living organism. According to (M.B.V, 1980) observations for a living organism to function normally and survive within the competitive environment there should be a strong cooperation and coordination between the cells. He argues that the existence of each cell contributes to the overall well being of the organism. Therefore individual cell functions are guided by the needs of the organism (M.B.V, 1980) (G, 2001) Living things could be classified into two groups first we have organism consisting of one cell these include amoeba, bacteria among others they are known as unicellular organisms. On the other hand organisms with more than one cell are called multi-cellular organisms (M.B.V, 1980). Such organisms exhibit complex processes and this is evident in the way they carry out their activities and we could attribute this to their more pronounced abilities and energy. According to (M.B.V, 1980) the diameter of a cell is a fiftieth of a millimeter this makes cell too small to be seen by the human eye however optical devices such as the light microscope have revolutionalized cell observation. For an instance microscopes have magnifying power which is the ability to enlarge the image of a specimen making is visible to the human eyes. In addition microscopes enable human beings to make the observation of tiny specimens through the resolving power that allows the displaying the fine details of a specimen under observation thus optical devices are designed to fit the different needs of the users. Cell biology is among the disciplines in science that seek to examine and come up with more and reliable information regarding cells as the basic functional unit in all living organisms therefore there is need to enhance better understanding of the cell through cell biology. To facilitate this discussion the report will analyze cell biology under different subheadings this will include the physiological properties of cells, cell structure, cell organelles, lifecycle, division and the death of a cell. The structure of a cell Both plant and animal cells structure have a lot in common however this report will focus more on animal cells. According to (M.B.V, 1980) (Evans, 2008) the diameter of an animal cell is approximately a fiftieth of a millimeter. This is too small for the human eye however with the aid of a light microscope it is possible to view the cell details. A cell consist of different parts and the outer part of the cell consist of a thin layer known as the cell membrane this part enclose the other components jointly known as the protoplasm. Each cell has a nucleus that is centrally situated within the main cell surrounding the nucleus is the cytoplasm. Observations by (M.B.V, 1980) reveal that besides the nucleus in the cell there are food granules this is the cell engine because chemical reactions that take place here and as a result the reactions release a lot of energy needed by the organism. Within the nucleus there is the nucleolus surrounded by the chromatin granules that form the chromosomes containing the hereditary components. The nucleolus and the chromatin granules are bound together by the nuclear membrane. In addition the cell has other components including the secretory granules, Golgi body, mitochondria, and the centriole (Evans, 2008). The centriole plays an important role in the cell it is responsible for the formation of cilia and flagella. Cell organelles The study of the cell structure in the subheading above show that there are more structures/ components carrying out different functions. These structures are the cell organelles they include cell membrane which can that form the boundary between cells. The cell membrane is not visible under the light microscope however an electron device can help in viewing this organelle. The cell membrane has several roles to play and they include controlling the movement of materials, enclosing other organelles, The other organelle is the endoplasmic reticulum (ER) this organelle has two divisions and namely the rough and the smooth ER. The ER is composed of proteins with the rough ER consisting of surrounded by other organelles called ribosome to facilitate protein synthesis. The functions of the ER include synthesizing protein and lipids. Another organelle is the Golgi body the Golgi body consists of vesicles containing secretions to facilitate transport in the cell and their functions are constructing cell walls, producing lysosomes, and producing secretions. The mitochondrion is another organelle which consists of in-folding and other enzymes. They also nucleic acid DNA and RNA, and proteins it is within the mitochondria that most activities take place. Mitochondria produce energy, and also regulate the ionic composition of the cytoplasm. Other organelles include the microtubules which give mechanical support and facilitate transport, the microfilaments that facilitating the movement of substances, the nucleus that forms the most important part of the cell. The nucleus controls all activities within the cell and keeps the cell alive. It also produces new cells, transmission of genes, facilitating growth, controls protein synthesis and nucleotides (Evans, 2008). The lifecycle of a cell/Cell division The most important part and organelle in a cell is the nucleus which is mainly composed of proteins. The nucleus contain the DNA and the RNA strands distributed within the nucleoplasm and when cell division occur strands in the nucleus form the chromosomes carrying the genetic makeup the cell (M.B.V, 1980) (Evans, 2008). The process is referred to as meiosis and cell division is a continuous process because old cells die and replacement take place to enable the organism continue living (Morgan, 2007). The death of a cell Like a living organism the cell could also die however the death of a cell could be natural due to age after completing their cycle. Natural death in a cell takes place when the cells can no longer carryout its functions properly and it cannot produce enough energy for its sustenance. In addition natural death in a cell could be genetically instigated through apoptosis i.e. the cell suicide process or program. This process swings into action within a cell when there is some kind of intracellular stress thereby setting up a self destruction procedure. In most cases stress within a cell result from cellular damages such as alteration of the DNA structure, deprivation of cytokine among other related factors. The process of activating suicide program begins by CED-3 that should be activated by CED-4 to begin the production of destructive agents which are present within the cell but in their inactive states (Khosravi-Far, 2008) (Levine, 2009). This process helps to eliminate weaknesses and the unpleasant results such as development of a degenerate species. The death of a cell results from initiation of the executioner the entails the activation of a group of cysteine proteases. The process entails the activation of death receptors that the resultant is caspase-9 there is a sequence of activities that lead to the termination of the cell. Death occurs as precaution to alleviate more damage or infection. Both extrinsic and intrinsic apoptosis pathways are relevant to the T lymphocyte homeostasis. Stress in a cell activate the B cell leukemia 2 and enable permeability in the mitochondria. It also leads to caspase activity (Levine, 2009). The role of Bcl-2 in supporting cell survival The cell is the most important functional unit in an organisms and the coordination between the cells making up an organism is very important. This coordination is responsible for the survival of a cell, it is also enhances effective competition of the organism within the environment. Like other living organisms individual cells die however there are mechanism within the organism that assume the role of continuously replacing the dying cells. Therefore loosing and gaining of new cells is not a new phenomenon however there mechanism controlling the death of a cell. The Bcl-2 is group of proteins with anti and proapoptotic regulation (Khosravi-Far, 2008) (Levine, 2009). The Bcl-2 family controls the death of cells by collaborating with other cells during stress within a cell. Via collaboration the Bcl-2 proteins decide whether to unleash caspase proteolytic cascade when there is some damage in the DNA within a cell as well as responding to deprivation of cytokine. The death of cells in an organism may result from severe stress resulting from fatal accidents. However there are genetic programs responsible for maintaining normalcy within an organism. These programs are contained in the chromosomes and pass from one organism to the other to facilitate survival. Cell suicide takes place under extreme conditions such as DNA damage that may result to redundancy or damaged cells thus the control of cell death is vital to prevent severe situation as degeneration. This process takes place at the embryonic stage through adult life. Failure to control the survival degenerate cell could have negative effects that may lead to the development of cancerous cells. The death of a cell results from initiation of the executioner the entails the activation of a group of cysteine proteases (Khosravi-Far, 2008). The process entails the activation of death receptors that the resultant is caspase-9 there is a sequence of activities that lead to the termination of the cell. Death occurs as precaution to alleviate more damage or infection. Both extrinsic and intrinsic apoptosis pathways are relevant to the T lymphocyte homeostasis. Stress in a cell activate the B cell leukemia 2 and enable permeability in the mitochondria it also lead to caspase activity (Levine, 2009) (Khosravi-Far, 2008). The cell suicide process/Apoptosis is the dying process in a cell it begins with genetically controlled program that takes effect during specific situations. The process begins as a reaction to damages to the genetic makeup of a cell the process seek to eliminate the abnormality within the cell however continuous studies revelation does proof that Bcl-2 promote cell survival instead of enhancing their death. On the other hand the findings above also link the same Bcl-2 to the development of cancerous cells due to sustained damages to the DNA. Further studies indicate that with release of cysteine protease responsible for activating cytokine Bcl-2 did inhibit the activation of the cell suicide program. Additionally, Bcl-2 from human beings promoted cell survival in worms. The components responsible for cell suicide caspase are present in individual cells however they are in their inactive state awaiting activation if need arise. Bcl-2 proteins others in the family protect cells from extermination such as cytokine deprivation however some members within the family support cell suicide (Khosravi-Far, 2008). The killing process demand all domains involved work together and in a sequence after sensing damages within a cell thus Bcl-2 family members strife to prevent successful coordination of the whole process of activating caspase. The process of activating suicide program begin by CED-3 that should be activated by CED-4, however Bcl-2 and its group member CED-9 prevent activation process (Levine, 2009) (Khosravi-Far, 2008). On the other hand cells in the death process try to limit the activity of Bcl-2 allowing the process to continue. Conclusion The cell is the most important unit within an organism it plays a major in ensuring that the needs of the main organism are a priority. The cell is too small and the human eye cannot observe it without assistance however science and technology has revolutionalized the study of the cell by e developing devices such as optic/light and the electron microscope which aid the human eye to observe the cell. These devices have magnifying and resolving powers that enable them to enlarge the image of a specimen under observation as well as facilitating the viewing of clear details for instance the electron microscope can display clear images of the plasmalema. Cell biology is necessary for a clear understanding of the cell and its role in an organism. Cell survival is very important because it helps in determining future of the organism. Therefore whether a cell dies or if live should attract a lot of attention to this study however the cell mechanism is better positioned to decide which cell lives and which one die. Furthermore this processes are genetically instigated to enable the organism adapt to the changing environment and compete effectively therefore it is necessary that the best survive and degenerates are faced out. In addition it is clear that the decision whether a cell should die falls entirely on the cell and in particular the Bcl-2 family of proteins. Cell suicide is a genetic process inherited from the mother cell to the new cell designed to maintain balance. Whenever a cell experiences intracellular stress for example damage to the DNA the cell becomes a danger and apoptosis begins to facilitate its elimination. However the Bcl-2 group of anti and proapoptotic regulators participate decision making whether the cell should die they prevent the process of destroying the cell. On the other hand as the Bcl-2 activities in preventing cell destruction could lead to the development of undesirable traits such as development of cancerous cells. References Books, L. (2010). Cell Biology Literature. Journal of Cell Science, Cell and Tissue Research . Books, L. (2010). Cell Biology Literature: . Journal of Cell Biology, . Evans, J. A. (2008). Cell biology and genetics. Mosby. G, F. K. (2001). Cell Biology. International Society of Gynecological Pathologists. (1997). International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists. International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists , 16-17. Khosravi-Far, L. Z. (2008). Programmed Cell Death: General Principles for Studying Cell Death,Piacentini. Academic Pr. Levine, B. D. (2009). Autophagy in Infection and Immunity. Current Topics in Microbiology and Immunology Series. Springer. M.B.V, R. (1980). Biology, A Functional Approach . london : ELBS. Morgan, D. (2007). The cell cycle: principles of control, Primers in biology. Published by New Science Press in association with Oxford University . Supplement. (2000). European journal of cell biology.v. 51-55 , 51-55. Read More