Biotechnology is the manipulation of biological
systems to manufacture important foods, drugs, biopolymers and other materials.
This is illustrated below by the production of the protein human
insulin in bacterial culture:
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1. Small circles of DNA exist in bacteria,
known as plasmids. These are modified to include the piece of human DNA
containing instructions for making proinsulin.
Proinsulin is the precursor for insulin. |
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2. The plasmid is then inserted into Eschericia
coli (E. coli) bacteria, which can now produce human
proinsulin. |
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3. The bacteria multiplies and produces
large quantities of human proinsulin in a fermentor. |
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4. Bacteria are then killed by heat sterilization to leave behind the proinsulin. |
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5. Proinsulin is enzymatically
cleaved to produce human insulin. Enzymatic cleavage is the
slicing of a molecule by a protein. |
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6. The solution is centrifuged to remove
cell matter and purified by liquid chromatography
and crystallization. |
Insulin is a hormone produced by the pancreas,
and is essential for the regulation of glucose in the body. The pancreas
of a diabetes patient has lost the ability to produce insulin. Prior to
the development of the above biotechnology process in the 1980's, only
animal insulin (usually from slaughtered pigs) was available to diabetics
in limited quantities.
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