Beta Theta Omicron
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Biotechnology and Human Welfare
Skyline College, San Bruno, California

New agony over breast cancer
By Rita Rubin
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Plaque-reducing protein shows promise
By Steve Sternberg
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Amgen thinks small to grow
By Matt Krantz
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Bacteria-powered battery runs on a sweet tooth
By Elizabeth Weise
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Bio-food fight centers on Africa
By Elizabeth Weise
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Discussion Questions and Additional Resources
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Summary Statement

Biotechnology is a way of making commercial products using living cells. Yeast have been used to make bread, wine, and beer for centuries. Without refrigeration, fermented foods last longer than fresh food. For example, cheese and yogurt can be kept longer than milk because of the acids and antibiotics produced by bacteria during fermentation. Advances in Biology during the latter part of the 20th century led to improved understanding of the relationship between specific microbes and their products. When World War I interfered with picking the Italian lemon crop, biologists turned to Aspergillus fungus to produce citric acid for food flavoring and preservation. During World War II, acetone for gunpowder and butyric acid for synthetic rubber were produced by Clostridium bacteria. Following World War II, large scale production of penicillin and streptomycin was accomplished by growing Penicillium fungus and Streptomyces bacteria in large vats.

Techniques quickly became more sophisticated as scientists learned to mutate wild Penicillium to make the fungus produce more penicillin. Until the 1980s, products made by living cells were all naturally made by the cells; the role of scientists was to find the appropriate cell and develop a method for large-scale cultivation.

For years people have genetically modified plants and animals by selective breeding. This technique is hit-or-miss because one doesn't always get the desired character such as more milk or sweeter fruit from mating two parents. In 1980, Paul Berg showed that animal genes can be attached to bacterial DNA. The resulting hybrid was the first example of recombinant DNA. When recombinant DNA is inserted into a cell, it can be used to make large quantities of the desired protein.

The applications of genetic engineering are increasing each year. Recombinant DNA techniques have been used to make bacteria and fungi that produce a number of natural proteins, vaccines, and enzymes. Such substances have great potential for medical use and because living cells make them, production doesn't involve expensive and dangerous chemicals or high temperature or pressure, and the cells don't produce toxic wastes. For example, some individuals do not produce enough human growth hormone, consequently their growth is stunted. Traditionally, the hormone was extracted from cadavers. However, diseases can be transmitted with the cadaveric hormone. Human growth hormone produced by genetically modified bacteria is pure and cost-effective.

Recombinant DNA techniques have also been applied to agriculture. Plants have been genetically modified to resist insect damage and herbicides and to prolong shelf life. And genetically modified bacteria have been used to prevent frost damage to crops.

The recently completed Human Genome Project was a massive undertaking to sequence the three billion nucleotide pairs in human DNA. The next step is to identify the genes in these three billion nucleotide pairs and identify the proteins they produce. The process is already providing invaluable information regarding the abnormal proteins produced by some forms of genes. This can lead to treatments to replace or change the abnormal protein.

Several recent articles in USA Today describe how biotechnology is affecting human health.

 
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