Genetic modification has been taking place naturally over the ____. New species evolved and are evolving due to natural mutations. Today, however, man is playing an ever-increasing role in altering the _____ of organisms by _____ processes, in a process called genetic engineering.
centuries
genomes
biotechnological
Define genetic engineering.
Any direct manipulation of an organism’s genes.
Define biotechnology.
Using scientific procedures to influence specific processes in living organisms which will benefit humans or improve the environment.
Genes may be turned on or off, deleted or ____ or foreign genes inserted into chromosomes - the possibilities are endless.
deactivated
What is the fastest branch of genetics?
Genetic engineering is currently the fastest growing branch of modern genetics. Although certain aspects of it are causing concern regarding ethical and environmental issues, it is proving to be very beneficial in many different fields.
What are the different ways of transformation?
There are many different ways of transformation, one of which is recombinant DNA technology.
What is recombinant DNA technology?
This is a form of biotechnology that is used to introduce new, beneficial genes into an organism to create genetically modified ways organisms (GMOs).
Define recombinant DNA.
A form of DNA that does not exist naturally but is created by combining DNA sequences that would not normally occur together
Define GMO.
Genetically modified organism (GMO) = organism with introduced foreign DNA (gene) that results in new and useful traits.
What does recombinant DNA involve in its simplest form?
Involves finding a desirable gene and moving it into the cells of another organism by means of a vector.
What is a vector?
a virus (bacteriophage) or plasmid that transfers foreign genetic material into another
What is a plasmid?
a circular, double-stranded DNA molecule found in bacterial cells that are not part of the bacterial chromosome
What happens after the desirable gene is inserted? (2)
- The new organism will then follow the instructions of the inserted gene and make the protein for which the new gene codes.
- If the genes are placed into bacteria, the bacteria can then be cultured to produce many working copies (clones) so that large quantities of the desired protein are produced.
What was one of the biggest breakthroughs in recombinant DNA technology?
The manufacture of biosynthetic ‘human’ insulin one of the biggest breakthroughs in recombinant DNA technology.
What is insulin?
Insulin is a hormone that lowers the glucose sugar levels in the blood.
A diabetic cannot produce sufficient insulin which results in too much ____ in the blood. To counteract this, a regular dose, injection or nasal spray of ___ is often essential.
glucose
insulin
How is insulin manufactured? (6)
- DNA with the gene that codes for insulin production is removed from healthy human pancreatic cells.
- Restriction enzymes cut these DNA strands at specific sites to isolate the gene that codes for insulin.
- Escherichia coli (E. coli), bacteria found in the human digestive tract, are the ‘factories’ used in the genetic engineering of insulin. A plasmid, removed from E. coli is cut open by restriction enzymes. Its uneven, cut ends are called sticky ends.
- The enzyme ligase joins the piece of DNA carrying the gene that codes for insulin, into the bacterial plasmid to form recombinant DNA.
- The plasmid with its recombinant DNA acts as a vector and is re-inserted into the host cell,E. coli bacterium, which will be effectively programmed to produce the protein, insulin The E. coli bacterium is therefore a genetically modified organism.
- The bacteria are kept in huge tanks containing a nutrient medium (fermentation broth) with the optimum pH, temperature and nutrient values, where they reproduce rapidly producing vast numbers of bacteria, each with the new gene capable of producing insulin. In this way the new gene is cloned and enormous amounts of insulin are produced which are purified and sold.
Define ligase enzyme.
Ligase enzyme occurs naturally in the nuclei of cells and acts as ‘genetic glue’, joining together the ends of two single strands of DNA
Define cloning.
Is the process of artificially reproducing a gene, set of genes, or a whole organism
The advantages are that the GMO insulin: (3)
- Is produced rapidly in large quantities
- Is relatively inexpensive
- Nuclei has few side effects as it is ‘human’ insulin.
Yeast cells may be used in recombinant DNA technology as they also have plasmids. The advantages are that yeast cells are more readily available and more ___-_____ than E. coli.
cost-effective
