GENETIC ENGINEERING
Genetic engineering any direct manipulation of an organism’s genes
Recombinant DNA technology finding a desirable gene and moving it into the cells or
another organism by means of a vector to create a genetically modified organism (GMO)
Transgene a gene inserted into another organism
Genetically modified organism an organism with introduced DNA (transgene) that results
in new and beneficial traits
Biotechnology the use of scientific procedures to influence specific processes in loving
organisms which will benefit humans of improve the environment
GENETIC MODIFICATION
DEF: creating DNA sequences that would not occur naturally
How: genetic engineering (changing/adding/deleting genetic material) or mutations
Need: restriction and ligase enzymes
1. Restriction enzymes: DNA CUTTING enzymes. Produced naturally by bacteria as a
defence against viruses, they restrict viral growth, very useful in cutting DNA at the
right places
2. DNA ligase: DNA joining enzyme. Occurs naturally in the nuclei of cells and acts as
“genetic glue”, joins together the ends of DNA strands to form recombinant DNA
MEDICAL APPLICATION
Production of insulin (lowers blood glucose levels) is brought about by recombinant DNA
technology
PROCESS:
1. DNA with the gene that codes for insulin production is removed from human
pancreatic cells
2. Restriction enzymes cut these strands to isolate the gene that codes for insulin
3. E. coli bacteria found in the human digestive tract are the factories used in the
genetic engineering of insulin: a plasmid, removed from E. coli is cut open by
restriction enzymes. Its uneven cut ends are called sticky ends.
(plasmid: a circular, double stranded DNA molecule found in bacterial cells that is
not part of the bacterial chromosome)
4. The ligase enzyme joins the piece of DNA carrying the gene that codes for insulin
with the bacterial plasmid to form recombinant DNA
5. The plasmid with its recombinant DNA acts as a vector and is RE-INSERTED into the
host cell, E. coli bacterium, which will now effectively be re-programmed to produce
the protein, insulin. (E.coli bacterium – GMO)
6. Bacteria are kept in huge tanks containing a nutrient medium (fermentation broth)
with the optimum pH, temperature and nutrient values, where they reproduce
rapidly.
7. Produce huge numbers of bacteria, each with the new gene, capable of producing
insulin. Through this process – the gene is cloned, and enormous amounts of insulin
are produced which are purified and sold
Advantages insulin is produced rapidly in large quantities, inexpensive, few side effects as it is
‘human’ insulin
, GENE THERAPHY
DEF: altering the genotype of a tissue/whole human, replaces a faulty gene or adds a new
gene in an attempt to cure disease or improve the body’s ability to fight disease
HOW ARE NEW GENES INTRODUCED INTO THE BODY: vectors like viruses deliver the gene
into cells of the body
DELIVERY OF VECTORS:
DIRECT: vector can be injected/ intravenously (means of a vein) into a specific tissue
in the body, where it is taken up by individual cells
CELL BASED: sample of the patient’s cells is removed and exposed to the vector in a
lab, cells containing the vector are returned to the patient
If successful – the new gene delivered via the vector will make a functioning protein
The gene being delivered is called a therapeutic transgene: a gene that has been
transferred naturally, or by any of a number of genetic engineering techniques from
one organism to another. The introduction of a transgene changes the genotype,
and the potential to change the phenotype of an organism.
Genetic engineering any direct manipulation of an organism’s genes
Recombinant DNA technology finding a desirable gene and moving it into the cells or
another organism by means of a vector to create a genetically modified organism (GMO)
Transgene a gene inserted into another organism
Genetically modified organism an organism with introduced DNA (transgene) that results
in new and beneficial traits
Biotechnology the use of scientific procedures to influence specific processes in loving
organisms which will benefit humans of improve the environment
GENETIC MODIFICATION
DEF: creating DNA sequences that would not occur naturally
How: genetic engineering (changing/adding/deleting genetic material) or mutations
Need: restriction and ligase enzymes
1. Restriction enzymes: DNA CUTTING enzymes. Produced naturally by bacteria as a
defence against viruses, they restrict viral growth, very useful in cutting DNA at the
right places
2. DNA ligase: DNA joining enzyme. Occurs naturally in the nuclei of cells and acts as
“genetic glue”, joins together the ends of DNA strands to form recombinant DNA
MEDICAL APPLICATION
Production of insulin (lowers blood glucose levels) is brought about by recombinant DNA
technology
PROCESS:
1. DNA with the gene that codes for insulin production is removed from human
pancreatic cells
2. Restriction enzymes cut these strands to isolate the gene that codes for insulin
3. E. coli bacteria found in the human digestive tract are the factories used in the
genetic engineering of insulin: a plasmid, removed from E. coli is cut open by
restriction enzymes. Its uneven cut ends are called sticky ends.
(plasmid: a circular, double stranded DNA molecule found in bacterial cells that is
not part of the bacterial chromosome)
4. The ligase enzyme joins the piece of DNA carrying the gene that codes for insulin
with the bacterial plasmid to form recombinant DNA
5. The plasmid with its recombinant DNA acts as a vector and is RE-INSERTED into the
host cell, E. coli bacterium, which will now effectively be re-programmed to produce
the protein, insulin. (E.coli bacterium – GMO)
6. Bacteria are kept in huge tanks containing a nutrient medium (fermentation broth)
with the optimum pH, temperature and nutrient values, where they reproduce
rapidly.
7. Produce huge numbers of bacteria, each with the new gene, capable of producing
insulin. Through this process – the gene is cloned, and enormous amounts of insulin
are produced which are purified and sold
Advantages insulin is produced rapidly in large quantities, inexpensive, few side effects as it is
‘human’ insulin
, GENE THERAPHY
DEF: altering the genotype of a tissue/whole human, replaces a faulty gene or adds a new
gene in an attempt to cure disease or improve the body’s ability to fight disease
HOW ARE NEW GENES INTRODUCED INTO THE BODY: vectors like viruses deliver the gene
into cells of the body
DELIVERY OF VECTORS:
DIRECT: vector can be injected/ intravenously (means of a vein) into a specific tissue
in the body, where it is taken up by individual cells
CELL BASED: sample of the patient’s cells is removed and exposed to the vector in a
lab, cells containing the vector are returned to the patient
If successful – the new gene delivered via the vector will make a functioning protein
The gene being delivered is called a therapeutic transgene: a gene that has been
transferred naturally, or by any of a number of genetic engineering techniques from
one organism to another. The introduction of a transgene changes the genotype,
and the potential to change the phenotype of an organism.
