Genetic engineering, the means to making genetically modified food, is a key component of biotechnology. According to www.dictionary.com, biotechnology is:

"The use of microorganisms, such as bacteria or yeasts, or biological substances, such as enzymes, to perform specific industrial or manufacturing processes. Applications include the production of certain drugs, synthetic hormones, and bulk foodstuffs as well as the bioconversion of organic waste and the use of genetically altered bacteria in the cleanup of oil spills."

Indeed, genetic engineering involves "microorganisms" and "biological substances," all of which are used to improve foods. Genetic engineering is, very simply, inserting a portion of an organism's DNA into the DNA of a another life form, which results in a transgenic organism. Transgenic organisms refer to any living thing that has "foreign" DNA. Without DNA, genetic engineering cannot happen.

The process of genetic engineering involves several steps. First, scientists have to identify and locate the gene inside the organism. Upon locating it, they will remove the gene from the organism and paste it onto the DNA of a different organism, creating recombinant DNA (the DNA with the gene extracted from the DNA of another organism). To cut the DNA from the "donor" organism, scientists need a biological substance called enzymes, often referred to as "molecular scissors," which have the ability to cut DNA into smaller pieces. The enzymes recognizes and only servers certain points in the DNA, which is why it is possible to remove specific genes. After removing the desired gene from the donor organism's DNA, billions of more copies of the gene must be made so scientists can be sure they have enough DNA to work with. Because the cells of organisms will reject completely foreign DNA, the next step scientists have to take is to paste the isolated DNA into the DNA of the receiving organism. After attaching the two pieces of DNA together, and creating recombinant DNA, scientists will inject the material into the receiving organism that they wish to change.

This can be done several ways. Animal cells will take up the recombinant DNA if it is inserted into their nucleus. Bacteria, on the other hand, have plasmids, which are circular pieces of DNA that reside in their cytoplasm. Scientists will open up the circular plasmids and paste the extracted gene into the plasmid. Then they will stitch the plasmid back into a circular shape and insert it, with its new gene, into the bacteria. The cutting and stitching back together is done with the use of enzymes (the molecular scissors). This method is called gene-splicing. For plant cells that have thick cell walls, another method is used. In order to get past this barrier, scientists use a type of soil bacterium that can already insert its own genes into plant cells; scientists simply use the bacterium to insert other genes into plants. They can also use a tool called the "gene gun," which shoots small particles of the metal tungsten covered with DNA at the plants with enough power to penetrate the cell walls and, hopefully, get absorbed into the plant's DNA.

*top image courtesy of Richard Ebbs, bottom image courtesy of Virtue website (for more information, go to bibliography page)