Biochem Genetically Modified Food

Genetically modified foods 1

Running head: GENETICALLY MODIFIED FOODS SCIENCE, MEDICINE, AND THE FUTURE

Genetically modified foods science, medicine, and the future Christopher Clark West Coast University

Genetically modified foods 2

Section 1: Title of article: Genetically modified foods Source: BMJ 1999; 318:581-584 (27 February) Author: Leighton Jones Section 2: This article is from the medical journal British Medical Journal which provides a clinical review of foods that are genetically modified. The article discusses how the DNA that codes for certain traits are manipulated and transferred to other species. Current and future uses of genetic modification are discussed. Section 3: Since the beginning of time, biological variations have derived from mutation and recombination of genetic material. Over time, humans have learned how to manipulate this by artificially selecting desired characteristics, thereby creating numerous combinations that would never have occurred. As this initially was a very nonspecific way to introduce different genes to different species, genetic modification uses technology to target specific traits that are desired and to introduce that genetic trait into another organism. Plasmids, which are short circular DNA normally found in bacteria, are used in genetic modification. In using restriction enzymes, DNA is cut at a very specific sequence. The cut results in sticky ends which stick to other ends cut with the same enzyme. The plasmid and the target gene are both cut with the same restriction enzyme and then the two are mixed together. DNA ligase reconnects the sugar phosphate backbone of the DNA and the plasmid now contains the target gene as well. This is called recombinant DNA. This recombinant plasmid is then mixed with bacteria and in the right

Genetically modified foods 3

conditions is taken up by bacteria into their cells and incorporated into the bacterial DNA. The bacteria are cultured and the plasmid gets replicated at each division of the bacterial cell cycle. Plasmids can also be taken out from bacteria and introduced into plants and cells. In animals, the gene is injected into the egg nucleus, and hopefully taken up into the egg DNA. In plants, the plasmid is introduced into Agrobacterium which is a plant pathogen. The plant cell gets infected by Agrobacterium and the plasmid then transfers the DNA to the plant cell. The plant cell with the recombinant DNA is now cultured to produce roots, shoots, and eventually grows into a plant that bears the desired trait. Genetically modified foods also allows for the switching off of undesired genes. The gene in tomatoes that induces fruit ripening is selectively under expressed and therefore keeps the tomato from rotting before it can get onto the grocery store display. Currently, most uses for genetic modification are in crop plants. Insect resistance and herbicide tolerance have been introduced into plants. Futures applications of genetically modified foods include developing vaccines in foods, making food less resistant to spoilage, and eliminating allergens from foods. There is concern over the use of genetic modification. Some traits transferred to foods have been shown to be allergenic. Many times, antibiotic resistance is used as a marker for successful gene uptake. Sometimes this food is then used to feed animals and if unprocessed the resistance can potentially be transferred to animals and resistance may begin. The age of genetically modified foods is here. There are many potential advances with this technology. Potentially, food can be produced in inhabitable environments and mass vaccines can be distributed in common food sources such as milk. As long as careful steps to ensure safety are taken, this breakthrough technology can drastically improve our lives in the world today. Section 4:

Genetically modified foods 4

Genetically modified food is closely connected to biochemistry. It employs the manipulation of the genetic structure at the biomolecular level to obtain a desired result. Certain DNA traits are isolated and using enzymes, the genetic sequence coding the traits are excised and then recombined into bacterial DNA. The bacterial DNA is then incorporated into animal or plant DNA and the desired trait gets expressed as it becomes incorporated into the new genetically modified DNA sequence. Certain traits can be selected to be under-expressed as well. Section 5: I personally enjoyed reading this article. It was well written and easy to follow. The diagrams were easy to comprehend. I previously had been aware of the idea of genetically modifying foods, however, did not know how it was done at a molecular level. I did not know that enzymes were used to splice the desired DNA and host DNA and then to fuse them together. I really do think the technological advances can really make dramatic changes in the future. Drought stricken areas can potentially harvest crops, freezing areas can have cold resistant harvests, and vaccines can be incorporated into food and ingested by humans. The possibilities are endless. I would recommend this article to others who have some knowledge of biochemistry and molecular biology. Some understanding of DNA and how it is replicated is necessary to comprehend the technology used to achieve this science.