5.6- Genetic Engineering

Uses of Genetic Engineering:

• To transfer genes into bacteria, so that they can make useful products such as insulin.
• To transfer genes into plants and animals so that they acquire new characteristics, for example, resistance to disease.
• To transfer genes into humans so that they no longer suffer from genetic diseases such as cystic fibrosis.

Recombinant DNA Technology:

• Genetic engineering involves the introduction of engineered DNA into cells in such a way that it will replicate and be passed on to progeny cells.
• One important application is the introduction of DNA into bacterial cells in order to produce a required product.
• Recombinant DNA is formed when a piece of 'foreign' DNA is incorporated into the circular DNA (Plasmid) from a bacterium. 
• There are four stages in gene manipulation:
• The formation of DNA fragments including the gene required for replication.
• The splicing (insertion) of the DNA fragments into the vector.
• The Introduction of the vector into the bacterium.
• The selection of the newly transformed organism for cultivation.

Key Terms:

• Donor DNA: a gene that is isolated for insertion
• Plasmids: circular loops of DNA found in bacteria. The plasmid is known as a vector.
• Restriction Enymes: enzymes which cut into DNA molecules between specific base sequences.
• DNA Ligases: enzymes which join together portions of DNA.
• Sticky Ends: the two ends of the 'foreign' DNA segment. They have a short row of unpaired bases that match the complementary bases at the two ends of the opened up plasmid.
• Recombinant DNA: DNA which results from the combination of fragments from two different organisms.
• Reverse Transcriptases: enzymes used…