Global challenges Study Guide

Genetic engineering is a powerful technology that involves modifying the genetic material of an organism to achieve a desired trait. It's used in medicine, agriculture, and industry. The process typically involves several key steps. First, the desired gene is identified and isolated from a donor organism's DNA. This isolation can be done using restriction enzymes, which act like molecular scissors to cut DNA at specific recognition sites. Next, a vector, often a plasmid (a small, circular piece of DNA found in bacteria) or a virus, is prepared to carry the isolated gene into the host organism. The vector DNA is also cut open using the same restriction enzyme, creating complementary sticky ends. The isolated gene is then inserted into the opened vector DNA using an enzyme called DNA ligase, which forms phosphodiester bonds to join the DNA fragments. This creates recombinant DNA – DNA from two different sources combined. The recombinant vector is then introduced into a host organism, usually a bacterium, in a process called transformation. Not all host cells will take up the recombinant DNA, so a selection process is often used to identify successfully transformed cells. This might involve using antibiotic resistance markers encoded on the plasmid. Finally, the host cells that have successfully incorporated the recombinant DNA are cultured and allowed to reproduce, producing many copies of the gene or expressing the desired protein encoded by the gene. For example, genetically modified bacteria can produce human insulin for diabetics or growth hormones. The ethical implications and safety concerns of genetic engineering are continuously debated and regulated.