BY5.6 Genetic Engineering

Genetic Engineering

• commericial applications invove the production og insulin, enzymes and hormones on a large scale

uses of genetic engineering:

• transfer genes into bacteria so they can make useful products (e.g. insulin)
• transfer genes into plants and animals so they can acquire new characteristics (e.g. resistance to disease)
• transfer genes into humans so they no longer suffer from genetic diseases

recombinant gene technology:

• when a piece of ferign DNA is incorproated into the plasmid of a bacterium

Insulin porduction:

isolating gene from a donor DNA molecule

• insulin is a small protein
• gene that codes for insulin is located by a probe and isolated
• enzyme restriction endonuclease cuts DNA into smal pieces allowing the gene to be isolated into specific base sequences that the enzyme recognises
• unpaired bases at the cur from sticky ends

inserting the gene into a vector

• vector (plasmid) from ecoli used
• to obtain plasmids cell walls of bacteria are dissolved ad plasmids separated from cell deris
• circular DNA making up plasmis are cut using restriciton endonuclease
• enxyme makes sticky ends that allows the donor DNA to be spliced into the vector DNA which occurs when donot and vector DNA are mixed together
• sticky ends are complementary
• DNA ligases join donor and vector DNA together
• the created DNA is called recombinant DNA

marker genes

• marker genes that confer antibiotic resistance are included in the recombinant DNA forming the plasmids
• bacteria and plasmids are mixed together, onlu a small portion of the bacteria takes up the plasmids
• bacteria culutred on a growth medium with antibitioc and only those containing the plasmid marker will sruvive
• foreign DNA replicaes along with the rest of the plasmis every time the bacterial cell divides
• cloning og the recombinant containing bacteria results in the production of ultiple copies of the recombinant gene
• the bacteria divide repeatedly and give rise to a large population of bacterial cells all of which contain replicas of the foreign DNA

manufacture and advantages

• genetically modified bacteria cultured on a large scale using a fertmenter to rpoduce insulin
• insulin…