Recombinant DNA technology (genetic engineering) is a method of changing the inherited characteristics of an organism by altering its genetic material. Genetic engineering involves the manipulation of deoxyribonucleic acid, or DNA
NAYAB SAJJAD
BIOLOGY ESSAY
SKILL I
Recombinant DNA technology (genetic engineering) is a method of changing the inherited characteristics of an organism by altering its genetic material. Genetic engineering involves the manipulation of deoxyribonucleic acid, or DNA. Important tools in this process are so-called restriction enzymes that are produced by various species of bacteria.Restriction enzymes can recognize a particular sequence of the chain of chemical units, called nucleotide bases, which make up the DNA molecule and cut the DNA at that location. Fragments of DNA generated in this way can be joined using other enzymes called ligases. Restriction enzymes and ligases therefore allow the specific cutting and reassembling of portions of DNA. Also important in the manipulation of DNA are so-called vectors, which are pieces of DNA that can self-replicate (produce copies of themselves) independently of the DNA in the host cell in which they are grown. Examples of vectors include plasmids, viruses, and yeast artificial chromosomes. These vectors permit the generation of multiple copies of a particular piece of DNA, making this a useful method for generating sufficient quantities of material with which to work. The process of engineering a DNA fragment into a vector is called "cloning", because multiple copies of an identical molecule are produced. Another way, recently discovered, of producing many identical copies of a particular DNA fragment is the polymerase chain reaction. This method is rapid and avoids the need for cloning DNA into a vector.
The process of genetic engineering has great potential. For example, the gene for insulin, normally found only in higher animals, can now be introduced into a bacterial cell by way of a plasmid vector. The bacteria can then be grown in large quantities, giving an abundant source of so-called "recombinant" insulin at a relatively low cost. Production of recombinant insulin is also not dependent on the sometimes variable supply of pancreas tissue from animals. Another important use of genetic engineering is in the manufacture of recombinant factor VIII, the blood-clotting agent missing in patients with haemophilia. Virtually all ...
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The process of genetic engineering has great potential. For example, the gene for insulin, normally found only in higher animals, can now be introduced into a bacterial cell by way of a plasmid vector. The bacteria can then be grown in large quantities, giving an abundant source of so-called "recombinant" insulin at a relatively low cost. Production of recombinant insulin is also not dependent on the sometimes variable supply of pancreas tissue from animals. Another important use of genetic engineering is in the manufacture of recombinant factor VIII, the blood-clotting agent missing in patients with haemophilia. Virtually all haemophiliacs who received factor VIII before the mid-1980s have contracted acquired immune deficiency syndrome (AIDS) or hepatitis from viral contaminants in the blood used to make the product. Since that time, donor blood has been screened for the presence of HIV (Human Immunodeficiency Virus) and hepatitis C virus, and the manufacturing process includes steps to inactivate these viruses if they should be present. The possibility of viral contamination is eliminated completely with the use of recombinant factor VIII. Other uses of genetic engineering include increasing the disease resistance of crops, producing pharmaceutical compounds in the milk of animals, generating vaccines, and altering livestock traits. Recombinant DNA technology also includes insertion of human genes into sheep so that they secrete alpha-1 antitrypsin in their milk - a useful substance in treating some cases of lung disease.
NAYAB SAJJAD
Human cloning is a type of genetic engineering, but is not the same as true genetic manipulation. In human cloning, the aim is to duplicate the genes of an existing person so that an identical set is inside a human egg. The result is intended to be a cloned twin, perhaps of a dead child. Genetic engineering in its fullest form would result in the child produced having unique genes - as a result of laboratory interference, and therefore the child will not be an identikit twin.
Geneticists are developing a new method for removing viruses from human bodies-DNA scissors. This new method works in a similar way that antibiotics does. When antibodies enter our internal system they attack a specific type of enemy cell or virus and destroy it. Likewise, DNA scissors enter the body and attack a specific type of enemy virus or cell. DNA scissors are much more effective than conventional antibiotics because they enter the enemy cell and unravel their DNA. With dysfunctional DNA, a cell is a pile of lipids and proteins; cancerous tumours will turn to harmless dumps of organic material, that can be filtered out by the body. DNA scissors will affect things that antibiotics cannot, like AIDS. Genetic research makes it possible for food to be grown safer, better, and faster, without doing any damage to the environment. With today's knowledge of genetic engineering, several food companies are investigating possibilities of making more food in less time. Through a process know as gene therapy, geneticists have the ability to modify parts of genetic material in organisms. Geneticists can add attributes to crops, like tomatoes, that would make them resistant to insects. With such features, dangerous chemicals like DDT that harm the environment, plants, animals, and humans would not be needed. Other enhancements would include prolonged life spans for food products after harvesting. For example, tomatoes have been engineered to last longer so they do not have to be harvested early
A major medical difficulty today is the lack of organ donors. Waiting lists are always getting longer, and people are losing their lives as a result. In the future, geneticists would be able to clone pieces of organs and, then, make organs for
surgeries involving transplants. Geneticists may even be able to clone cells from damaged organs and then engineer exact duplicates. Genetics will definitely have a large impact on correcting of malfunctions in the human body. Without doubt, genetic engineering has already helped make human life easier and will continue to do so in the future, provided that research on genetic engineering continues.
NAYAB SAJJAD
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