Реферат: Molecular Biotechnology In Our Life Essay Research
Molecular Biotechnology In Our Life Essay, Research Paper
Molecular Biotechnology in Our Life
If you have had a can of soft drink, ate a fruit, or took some head ache medicine this morning – then it’s very likely you have used a genetically enhanced product. Genetics is a part of biotechnology that manipulates biological organisms to make products that benefit humankind. Biotechnology is essential in our life, but there are some concerns regarding its safety. Although, biotechnology may pose some danger it is proving to be very beneficial to humankind.
The first applications of biotechnology occurred approximately around 5000 BC. Back then people used simple breeding methods. Chains of plants or animals were crossed to produce greater genetic variety. The hybridized offspring then were selectively bred to produce the desired traits. For example, for about 7000 years, corn has been selectively bred for increased kernel size and additional nutrition value. Also, through selective breeding, cattle and pigs have become the major sources of animal foods for human (Encarta 99).
The modern era of biotechnology started in 1953 when British biophysicist Francis Crick and American biochemist James Watson presented their double-stranded model of DNA. DNA is an extensive, chain-like structure made up of nucleotides, and in a way it looks like a twisted rope ladder (Drlica 27). In 1960 Swiss microbiologist Werner Arber had discovered restriction enzymes. This special kind of enzymes can cut DNA of an organism at precise points. In 1973 American scientists Stanley Cohen and
Herbert Boyer removed a specific gene from one bacterium and inserted it into another using restriction enzymes. This achievement served as foundation to recombinant DNA technology, which is commonly called genetic engineering. Recombinant DNA technology is a transfer of a specifically coded gene of one organism into bacteria. Further, the host bacteria serve as a biologic factory by reproducing the transferred gene. Today biotechnology’s applications are used in a variety of areas. It’s used in waste management for creation of biodegradable materials, in agriculture for higher yields and quality, in medicine for production of advanced pharmaceuticals, cloning tissues and curing genetic diseases. However there is a down side to genetic engineering. It deals with dangerous bacteria which could escape the boundaries of a lab and possibly cause epidemics. Moreover, if a transgenic organism escapes, it could eliminate a range of species and thus disrupt natural balance. Since biotechnology is a necessity, some government guidelines were established for strict regulation of recombinant DNA experiments (Encarta 99).
Agriculture is the largest business in the world, with assets of approximately $900 billion and about 15 million employees. Back in the 80’s, there was a concern, based on population growth rates, that by the turn of the century traditional agriculture would be in a serious trouble (Hanson 68). But due to the revolutionary development of biotechnology during last couple of decades agriculture has drastically advanced. Sensational achievements were made in both plant cultivation and animal husbandry.
The modification of plants has become one of the most important aspects in agriculture. Increased crop yields can be achieved through the increase of land, or increased yield per tract. Land is expensive and should be used efficiently, to do so – large quantities of fertilizer, herbicides, pesticides and frequent irrigation may be necessary. Due to the increase in petroleum cost – prices for nitrogen fertilizers continuously rise. Herbicides and pesticides are considered to be hazardous and very costly materials. Moreover, recurrent irrigation gradually leads to serious damage of the soil due to the salt accumulation. Eventually, increased amounts of salt in the soil result in large losses of crops (Hanson 69). Biotechnology can incorporate genes that are resistant to environmental stress, viruses, and insects. Such modified plants will be resistant to the same factors as the incorporated gene.
Crop plants could be genetically engineered to manufacture functional insecticides so that they are immanently tolerant to insects. No hazardous and costly pesticides are needed for such plants resulting in very low crop maintenance costs. Moreover, biological insecticides are highly specific for a range of insects and considered to be harmless to humans and other higher animals (Glick and Pasternak 341).
Plant viruses very often attack crops and cause significant damage and loss of crops. Recombinant DNA technology offers a few ways to obtain natural virus resistance: viral transmission can be blocked, development of the virus can be blocked, or viral symptoms can be bypassed or resisted (Glick and Pasternak 345).
Biotechnology also contributes to the development of plants with higher tolerance to environmental changes. Plants cannot avoid hazardous environmental conditions such
as heat, drought, and UV radiation, so they have developed physiological ways to deal with those stresses. One of the undesirable effects of physiological stress is production of oxygen radicals. Trough the use of recombinant DNA technology some plants are given the ability to tolerate high levels of oxygen radicals, these plants are capable of withstanding a various range of environmental stress (Glick and Pasternak 350).
Another important area of biotechnology is improvement of livestock. Many generations of selective matings are required to improve livestock and other domesticated animals genetically for traits such as milk yield, wool characteristics, rate of weight gain, and egg laying frequency. At each successive generation, animals with superior performance characteristics are used as breeding stock. Eventually, high production animals are developed as more or less pure breeding lines. This combination of mating and selection, although time-consuming and costly, has been exceptionally successful. Today almost all aspects of the biological basis of livestock production can be attributed to this process. However, once an effective genetic line has been established, it becomes difficult to introduce new genetic traits by selective breeding methods (Glick and Pasternak 359).
Until recently, the only way to enhance genetic properties of domesticated animals was selective breeding. However, research in new areas of biotechnology lead to the development of new technologies and almost completely replaced traditional methodologies. Using recombinant DNA technology, scientists are able to insert a specific cloned gene in to the nucleus of fertilized egg of a higher organism. Then the
fertilized egg is implanted into a receptive female. Most of the offspring derived from the implanted eggs will have the cloned gene in all their cells. The animals with the transgenic gene in their germ line are bred to establish new superior genetic lines. For example if the injected gene stimulates growth, the animals that received the gene would grow faster and require less food. Even if consumption of food was cut down by only a few percent – it still would have a profound effect on lowering the cost of production and the price of final product (Glick and Pasternak 361).
Another area that benefits from biotechnology is medicine. This particular sector of biotechnology had risen from about $6 billion share of global market in 1983 (Hanson 66) to about $100 billion in 1997 (”The Biotech Boom” 89). McDonald states that “today, there are more than 2,200 drugs that are in development and 234 awaiting approval from FDA” (91). The primary reasons for such rapid development are millions of deaths each year caused by disease, viruses, and genetic disorders.
Biotechnology is widely used in pharmacy to create more efficient and less expensive drugs. Recombinant DNA technology is used for production of specific enzymes, which enhance the rate of production of particular range of antibodies in the organism (Hanson 67). Antibiotics produced using such technology have very specific effects and cause fewer side effects. Also, using similar methods a range of vaccines can be created. Currently, scientists are working on vaccines for fatal illnesses such as AIDS, hepatitis, malaria, flu, and even some forms of cancer. Shrof expects that in the near future vaccines will come in more convenient ways “some will come in the form of
mouthwash; others will be swallowed in time-release capsules, avoiding the need for boosters.” (57). Some genetically altered foods that will convey antigens against some disease are expected to be available in about five years (”Miracle Vaccines” 57,67).Genetic disease could be treated through the use of genetic engineering. Defective genes in an organism cause genetic disorders. If a defective gene could be identified and located in a particular group of cells – it could be replaced with a functional one. The transgenic cells are then planted into the organism, resulting in a cure of the disorder (Jackson and Stich 64,65).
Cloning is a relatively new sector of biotechnology, but it promises answers to very important problems related to surgery. Tissues and organs could be cloned for surgical purposes. If scientists could isolate stem cells, (stem cells have a potential to grow into any kind of tissue or organ) and then direct their development, they would be able to create any kind of a tissue, organ or even a whole part of a body (”On the Horizon” 89).
In a way, biotechnology is just like one of its products – for all the positive effects of biotechnology there are some possible side effects. The double-stranded molecule of DNA, originally honored for its intelligibility, in present society portraits a double-sided sword, which could be employed as an agent of death as well as an agent of life (”All for the Good” 91). There are some concerns that genetic engineering could pose some serious danger to earth inhabitants. Nobody knows what ecological hazards could be
caused by novel transgenic organisms (”DNA Disasters?” 80). The opposition of genetic engineering says that – the science is very young and needs a lot more research.
The majority of recombinant DNA experiments use E. coli bacteria as a host for production of transgenic proteins. E. coli could be harmful to human beings and other species. Although the experiments are conducted in secure, contained facilities, there is a chance that some of bacteria could escape the boundaries of such laboratory. Escaped bacteria then could find an environment for replication and could spread at a fast pace. Some species could be infected and transmit the bacteria to others, thus causing global epidemics (Jackson and Stich 99-113).
Moreover, genetic engineering enables the scientists to combine genetic materials of unrelated organisms. Such recombinant events across species have never been fond in nature. There is a chance that such hybrid organisms could escape from a laboratory. The escaped transgenic organisms could eliminate a range of species, and disrupt the natural balance. Not to mention that such organisms could abolish the human kind. However, scientists tend to think that there is a little chance of such happening (Jackson and Stich 127).
Hanson says that “the primary objective of genetic engineering is to control the genetic structures of many individual life forms which inhabit this planet, including humans, for their own benefit” (21). However, some individual scientists may have different goals. Indeed, some scientists may participate in illegal activities in order to achieve large financial rewards. There is a concern that some genetic project information could be sold to a group of terrorists or such and then used for development of biological
weapons. Use of biological weapons could wipe out vast portion of specific species in a particular region or even the whole planet.
There are some convincing reasons for biotechnology to be carefully regulated. In 1976, the National Institutes of Health (NIH) established a recombinant DNA Advisory Committee (RAC). RAC is responsible for creating guidelines governing recombinant DNA experiments. All the institutions, companies or individuals working in the field of genetics must obey those guidelines. By the end of 1981, after reviewing the record carefully, RAC drew the conclusion that some of its requirements could be loosened up because safety of new technology was established (Hanson 80).
Food and Drug Administration (FDA) has very high standards for proof of safety and efficacy. However, FDA has taken a constructive attitude in making the products of biotechnology quickly and safely available to the public. FDA does not require any unnecessary studies and provides the companies with technical assistance while taking the product through the approval system. Today, there are 234 new drugs awaiting approval from FDA (Hanson 82).
Innovation cannot exist without a strong patent system. If there were no patent system, the invention of one company could become available to other companies that did not incur high research and development cost. Without the potential for protecting company’s developments, there would be a little chance to raise enough capital for growth and support of the company during the period while the products go through regulatory approval process. The patent system also contributes to a development of
stronger economy by producing more competition. Under patent protection a new company can compete against larger, older and more entrenched companies. This, in turn, eliminates the possibility of monopoly and results in faster development and lower prices of the products (Encarta 99).
On one hand, there are some concerns regarding safety of biotechnological experiments. However, over the years biotechnology has proved to be exceptionally safe. On the other hand, there is a strong need for more efficient agriculture and higher achievements in medical field. Biotechnology has also proved to be extremely productive, and innovative coming up with the answers for the problems mentioned above. In conclusion, if the 20th century was the century of physics, the 21st century should be the century of biology.
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