Learning outcomes:
5.12
describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together
5.13
describe how plasmids and viruses can act as vectors, which take up pieces of DNA, then insert this recombinant DNA into other cells - b
5.14
understand that large amounts of human insulin can be manufactured from genetically modified bacteria that are grown in a fermenter
5.15
evaluate the potential for using genetically modified plants to improve food production (illustrated by plants with improved resistance to pests)
5.16
understand that the term ‘transgenic’ means the transfer of genetic material from one species to a different species.
The structure of DNA:
dna.GIF
DNA is a double-stranded molecule. The strands coil up to form a double-helix. The strands are linked by a series of paired bases.

Thymine (T) pairs with Adenine (A)
Guanine (G) pairs with Cytosine (C)

The bases are a crucial part of DNA. The sequence of bases is what created the genetic code!

Process of genetic engineering:

The example you need to know is the creation of E coli bacteria that makes human insulin. However, a more fun example is Alba, the glow-in-the-dark bunny that makes the protein luminol (taken from a jellyfish!)

alba2.jpg

1. Extract target gene (human insulin gene) from donor cell. This is done by cutting the gene out of human DNA using a restriction enzyme
2. Cut open the bacterial DNA, also using the restriction enzyme
3. Insert the gene and “stitch the DNA together” using DNA Ligase enzyme
4. Get the new DNA into the bacterium. This is done using a vector. Common vectors include Viruses and Plasmids
Now your transgenic bacterium is complete. All you need to do is grow it in a fermenter and it makes lots of insulin for you!

Transgenic Organism - Organism containing DNA from two or more sources (i.e. an organism that’s been genetically engineered to express a foreign gene). Scientists are experimenting with genetic engineering all the time. Plants are good to genetically engineer because they are more simple and there are fewer ethical issues.

Genetically modified (GM) crops are engineered to;

- Have bigger yields
- Be frost resistant (e.g. frost resistant strawberries)
- Have resistance to disease
- Grow in harsher environments (e.g. drought-resistant rice)
- Have vitamins in them that they would not normally have (e.g. golden corn)
- Have a longer sell-by date (e.g. non-squash tomatoes)
- Be a different colour / taste to normal (e.g. chocolate carrots)
- Have stronger taste (e.g. chilis)
- Be easier to eat (e.g. easy-peel oranges)