5c) Genetic modification/engineering

Restriction Enzymes - Are used to splice (cut) the DNA at the specific site- desired gene, e.g. human insulin. It can either be cut as a blunt or sticky end.

Ligases Enzymes - are used to stick pieces of DNA together

Vectors- something to transfer new DNA:
e.g. plasmids and viruses
Plasmids -

1. Isolate/ take out plasmid from bacterium using a pipette
2. cut apart the plasmid 
3. splice out the required gene using enzymes 
4. The glue using ligases the required gene and plasmid together. This is then called RECOMBINANT DNA. 
5. TRANSGENIC CELLS multiplies and starts producing (e.g. human insulin)  

Viruses-

1. Spice the required gene 
2. Add to the virus
3. Virus injects into the DNA (new organism) and RECOMBINANT DNA forms 
4. You then have a transgenic bacterium

Large amounts of human insulin can be produced by genetically modified bacteria that are grown in a fermenter 

Genetically modified plants:

• Crops can be genetically modified to increase food production in lots of different ways - one way is to make them resistant to insects, another is to make them resistant to herbicides (chemicals that kill plants) 
• Making crops insect-resistant means farmers can spray as many pesticides so wildlife isn't destroyed. It also increases crop yield. 
• Making crops herbicide-resistant means farmers can spray it to kill weeds but not the crops
• Some people are against genetic engineering altogether as they worry that a change in organisms genes might create unforeseen problems

1. Splice the DNA with desired features using the enzymes 
2. Meanwhile take plasmid out of Bacteria (Agrobacterium tumefaciems) and cut to allow space for the gene 
3. glue it together to make it a recombinant DNA 
4. Add the new DNA into a petri dish
5. There is agar jelly inside which has nutirents (NPK, Mg, Ca, S and Auxin hormones) to help the cells to divide and grow