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Home > Biology > Biotechnology > Reprogramming microbes


Reprogramming microbes

Genetic engineering

The control of all the normal activities of a bacterium depends upon its single chromosome and small rings of genes called plasmids. In genetic engineering pieces of chromosome from a different organism can be inserted into a plasmid. This allows the bacteria to make a new substance.

Process of genetic engineering involving insertion of 'sliced up' chromosome into bacterial plasmid.

You need to know the steps of this process. They are:

  • the gene the genetic engineers want may be in a human chromosome - it might be the gene for insulin production
  • they use an enzyme to cut the insulin gene out of the chromosome
  • plasmids are then removed from bacterial cells
  • the plasmids are cut open with an enzyme
  • a human insulin gene is inserted into each plasmid
  • the genetic engineers encourage the bacteria to accept the genetically modified plasmids
  • bacteria with the insulin gene are then multiplied
  • each bacterium will produce a tiny volume of insulin
  • by culturing the genetically engineered bacteria, limitless supplies of insulin may be produced

Genetic engineering is used for the production of substances which used to be both expensive and difficult to produce. Examples include:

  • insulin for the control of diabetes
  • antibiotics such as penicillin
  • various vaccines for the control of disease


Genetic engineering and insulin production

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Genetic engineering is a way of producing organisms which have genotypes best suited for a particular function. In the past man has used selective breeding to achieve this. This was done by choosing only his most suitable animals and plants for breeding.

Genetic engineering has several advantages over selective breeding. Some are:

  • particular single characteristics can be selected
  • the selection may be quicker
  • a desirable characteristic can be transferred from one species to another

There are dangers involved with genetic engineering since it involves creating completely new strains of bacteria. There is a possibility of creating some which are harmful to animal or plant life.


Insulin meter

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Video clip about how treatment for diabetes has developed with genetic engineering


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