DNA Essays -- Biology Biological Essays

DNA "There is no substance as important as DNA," Watson, 1991. Gene therapy is a controversial issue in today’s science society. Debates in the United States are covering a wide range of topics. I will discuss just a few viewpoints from both sides. First of all, a little background on DNA and genetics. DNA, or deoxyribonucleic acid, is a complex structure consisting of a double stranded helix made up of complementary base pairs. Adenine (A) pairs up with thymine (T) and guanine (G) matches with cytosine (C). They are held together with the help of hydrogen bonds. The helix is spiral shaped, and the outside of DNA is alternating sugar and phosphate groups. Watson and Crick presented this structure in 1953. "The genetic code is imprinted in the precise sequence of the nitrogenous bases running down the length of DNA molecule." Lee, 1993. A base triplet code is made up of three nucleotides. Each DNA triplet code is translated via a messenger RNA into a protein. DNA has a semiconservative replication process where the double strands unwind and serve as templates. A genome is a collection of DNA molecules that make up am organism. There is great diversity between different species and even between the same species. "The human genome contains up to three billion base pairs, the genetic difference among individual humans is as much as three million base pairs of DNA" (Davis, 1990). A mutation is where a gene is changed to another form. A mutation does not imply a bad thing happened. They can be deleterious, cause disease, reduce fitness or even be lethal. A mutation can also be beneficial if it increases adaptability or advantages in a species. Or a mutation can be silent and cause no apparent change in the organism. T... ...ecoming a safer, more efficient process that may some day cure the world of all genetic disease. Some day, being sick may just mean getting gene therapy. Bibliography Joel Davis, Mapping the Code: The Human Genome Project and the Choices of Modern Science, John Wiley & Sons, Inc., 1990. Thomas F. Lee, GENE FUTURE: The Promise and Perils of the New Biology, Plenum Press, New York, 1993. U.S. Congress, Office of Technology Assessment, New Developments in Biotechnology— Background Paper, Pubic Receptions of Biotechnology, OTA—BBP—BA—45, U.S. Government Printing Office, Washington, D.C., May 1987 quoted by George J. Annas and Sherman Elias, GENE MAPPING: Using law and Ethics as Guides, Oxford University Press, New York, 1992, page 144. Unknown author, Gene Therapy - An Overview, 1990, http://www.gene.com/AE/AB/IWT/Gene_Therapy_Overview.html