Retrieved from https://studentshare.org/miscellaneous/1509007-virus-paper
https://studentshare.org/miscellaneous/1509007-virus-paper.
As a group, viruses are tiny, ranging from ten to four hundred nanometers in diameter. The smallest are barely larger than ribosomes or other internal structures found inside normal cells; the largest (e.g., variola) is almost the size of small bacteria. Some viruses can be detected under a sophisticated light microscope, but for most only an electron microscope will serve. For generations, therefore, even the best scientists were essentially guessing about the structure, nature, and functioning of viruses, entities they could observe only indirectly (Bookchin and Schumacher, 68). The first actual sighting of a variola virus—the first virus of any sort so visualized—came in 1947, under an electron microscope. The smallpox virus capsid is often described as ellipsoid or brick-shaped. Many viruses, including variola, are often enveloped, with the capsid housed inside an outer membrane made of proteins, carbohydrates, and lipids, which provides, in the case of variola, an overall spherical appearance (Imperato, 390). The infection process begins when a virus approaches a target cell; forcible entry into the cell may then be accomplished in several different ways. Some antibacterial viruses mechanically drill a hole in the cell's outer structure and inject the viral DNA through it, much like the operation of a hypodermic syringe, with the now empty capsid remaining outside. Viruses that afflict plants often enter passively through a microtear in the cell wall (Imperato, 390). The defenses that the human body—and modern medicine—erect against many other types of infections are often less effective against viruses. But viruses pose exceptional challenges to the immune system. Some of these aggressors undergo very frequent mutation, altering the external configuration of those glycoproteins, and thereby fooling or evading the antibodies (Strohman, 169).
Dear Granny the main problem is that scientists have not yet concluded the question of whether viruses are alive or dead. On the one hand, a virus is nature's ultimate parasite: it is incapable, by itself, of undertaking the usual array of biological functions. It cannot produce or consume energy, move, grow, or reproduce without first invading a living cell and usurping the host's internal mechanisms. For this reason, many scientists do not consider variola or any other virus to be truly alive, even in the sense that other simple microorganisms, from bacteria to rickettsia (another family of infectious microorganisms) are considered so (Strohman, 169). Other authorities would, perhaps more generously, consider viruses to be minimal “living organisms”. At the same time, there is surely something about a virus that makes it different from a conglomeration of inert chemicals. It has at least a kind of life potential, a dormant biological presence, that is undeniable. The recent discovery of categories of even smaller, and even less lifelike, infective entities has further obscured the question of deriving a meaningful definition of life (Strohman, 169). Prions, protein-like particles devoid of any nucleic acid, have been implicated in a variety of degenerative brain diseases, such as scrapie in sheep, mad cow disease, and Creutzfeldt-Jakob disease in humans, although their precise operational mechanisms are still unknown. Viroids are a cluster of similar plant-invading creatures, containing a snippet of RNA but none of the other usual viral accouterments (Strohman, 169). Other newfound microscopic entities, intracellular mobile genetic elements of all descriptions, also challenge our ability to construct reliable, useful demarcations in the netherworld of biology. The principal antiviral treatments are therefore precautionary—they involve artificially stimulating the immune system to produce the appropriate antibodies before the host is invaded by the virus, so the body is prepared in advance to defend itself (Campbell and Reece, 34-35).
In the article ‘Bacteria May Hold Secrets to Immortality’ Than (2006) discusses the important problems of human life and the possibility of immortality. Thus, the author does not take into account recent trends and scientific discoveries. Although the structures of different viruses can vary enormously, most share certain characteristics. At the center is a vision, a protective core of the protein and a shred of nucleic acid, either DNA or RNA—the virus's genome— formed into one or more strands, loops, or matched pairs. This protein chain may be only five genes long, or it could contain several hundred genes. The simplest viral genome has the blueprint for a handful of proteins; the most complex can elicit hundreds. In the case of the smallpox virus, the genome is a single, relatively lengthy, strip of double-stranded DNA, comprising about two hundred genes (Bookchin and Schumacher, 68).
Granny, I suppose that in several years biologists and scientists will find a virus that can bring a human back to life. In nature, there is a balance between species and natural forces. Historical development shows that if viruses exist there should be an ‘antivirus’ which could renew a human cell. Nature is self-reproducing and ‘self-repair’. I suppose that these viruses exist but modern medicine cannot identify and use them for treatment purposes.
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