Summary
Highlights
Genetic engineering is a form of biotechnology that involves changing the genetics of an organism to suit human needs. This can include engineering bacteria to create substances for us, genetically modifying food, or assisting people with illnesses by replacing faulty genes with healthy ones.
Biotechnology is the broader term, defined as the manipulation of a biological process to satisfy human needs, including processes like fermentation. Genetic engineering is a specific type of biotechnology where genes are removed from one organism and added into another, emphasizing the transfer of genetic material that did not originate in the recipient organism.
Bacteria are key to genetic engineering because of their simple anatomy, particularly the presence of a plasmid—an extra-nuclear, ring-shaped piece of DNA that is easily accessible and manipulable. Unlike the main nucleoid DNA, plasmids can be cut and modified with ease. Bacteria also replicate very quickly, allowing for rapid production of desired substances or cells.
The process of creating human insulin using genetic engineering involves several steps: isolating a bacterial plasmid, using restriction enzymes to cut the plasmid and human DNA (specifically the insulin gene), inserting the human insulin gene into the bacterial plasmid, forming what is called recombinant DNA, inserting this modified plasmid back into a bacterial cell, and then allowing the bacteria to multiply. As the bacteria replicate, they read the plasmid DNA and produce and secrete human insulin, which can then be collected for use by diabetics.
Genetic engineering is also applied to plants. Agrobacterium is used as a vector to introduce modified DNA into plant cells. The bacteria transfer the desired genes, which then alter the plant's DNA. This can lead to plants that produce more fruit, have better quality, increased size, or are resistant to diseases and environmental factors like frost.
Advantages of GMOs include increased yield (amount of product), improved quality of food (more nutrients and vitamins), and making crops and livestock resistant to pests and herbicides, which reduces the need for chemical sprays and injections.
Disadvantages include the initial high cost of developing GMOs, reduction in the gene pool leading to less variation and increased susceptibility to the same diseases across a population, and potential negative impacts on biodiversity. This can occur if genetically modified pollen contaminates wild varieties, leading to irreversible mixing of GMO DNA into wild plant populations.
Key terms include: biotechnology (broad term for processes benefiting humans), genetic engineering (specific type of biotechnology to modify genes), plasmid (bacterial DNA used for modification), restriction enzyme (cuts DNA), recombinant DNA (plasmid with inserted new gene), and GMO (organism with modified genes).