[Music] many years ago diabetics who needed insulin to survive had to inject cow or pig insulin into their bodies this was not ideal for many reasons today the insulin that diabetics inject is human insulin and it is produced by micro organisms such as the e coli bacterium and certain strains of yeast but how do these micro organisms produce human insulin genetic engineering scientists are able to turn certain microorganisms into mini factories that make useful substances that improve our health the environment and the economy but what is genetic engineering an organism's DNA makes up its genes which code for all the proteins the organism needs to survive each gene codes for a different protein or part of a protein genetic engineering is the manipulation or changing of the DNA of an organism genetic engineering involves removing a gene from one organism which is called the donor and transferring it to another organism which is referred to as the recipient the recipient is called a transgenic organism or a genetically modified organism there are two basic purposes of genetic engineering sometimes we require large volumes of a particular protein to be made scientists use transgenic micro organisms to produce large volumes of this protein for example insulin growth hormone or vaccines an organism bee can have a gene from a different organism a introduced to give it be some advantage that a has naturally organisms like bee are called genetically modified or transgenic organisms for example a gene that manufactures a toxic chemical in a bacterium can be introduced into a maize plant to make the plant toxic to certain insects that would eat it such as caterpillars let's now look at the process of genetic engineering how do you transfer a genetic characteristic from one organism to another although it's a very complex process it can be summarized rather simply we'll use the example of how the insulin gene is inserted into a bacterium in order to manufacture large amounts of human insulin the gene that codes for human insulin is found on chromosome 11 at position 15 point 5 the insulin gene is cut from chromosome 11 using special enzymes called restriction enzymes bacteria possesses small circular strands of DNA floating in their cytoplasm these strands of DNA are called plasmids a plasmid is extracted from the bacterium cell the plasmid is cut open using the same restriction enzymes that were used to cut the insulin gene from the human chromosome the restriction enzymes leave sticky ends where one of the two DNA strands is slightly longer than the other because the same restriction enzyme was used to cut both the human DNA and the bacterial plasmid the sticky ends are complementary and will allow for joining using complementary base pairing the insulin gene is joined to the plasmid by the sticky ends an enzyme called ligase is used to complete the joining of the two pieces of DNA the modified plasmid is then reinserted into the bacterial cell the modified bacterium is a genetically modified or transgenic organism because it contains some human DNA along with its own bacterial DNA its bacterial DNA is called recombinant DNA bacterial DNA Rican lined with human DNA the bacterial cell is placed in a fermenter which allows for rapid asexual reproduction in ideal conditions with the optimal temperature pH and lots of food because the bacteria reproduce asexually the offspring are all clones of the original transgenic bacterium they all have identical recombinant DNA the bacteria expressed their own genes in order to survive in other words they make their normal bacterial proteins but they also Express the human insulin gene and make human insulin the fermenter has become a culture of mini factories all producing human insulin the insulin is then extracted purified and packaged humans can now inject themselves with human insulin and that is how genetic engineering works if you liked the video give it a thumbs up and don't forget to subscribe comment below if you have any questions why not check out our fuse graph as well until next