 What is GE?
What is it Used For
The Dangers!
Organic Foods
GE and You
About This Site
Contact
Genetic Engineering
The Genetic Code
Recombinant DNA
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What is GE? |
Biotechnology
Genetic Engineering is a biotechnology. Biotechnology is the use
of natural biological processes of living things for the benefit of
mankind. Forms of biotechnology have been used for
thousands of years - to bake bread, brew beer and make cheese, etc.
Recently Biotechnology has advanced into more powerful areas,
particularly genetic engineering. This new biotechnology
(genetic engineering) has
created many new possibilities,
and many new questions left to be answered.
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Genetic Engineering |
The Technology
All the information a cell needs to perform it's tasks for the entire life of
the organism it is part of, is contained in its genetic makeup - a chemical message
called genes. These genes
are passed on from one generation to the next, so new cells inherit
an exact copy of their parent's genetic code.
Scientists now understand the basic structure and system in which these genes
are coded to create certain proteins, creating certain characteristics.
It is based on a substance called Deoxyribonucleic Acid (DNA).
All a gene is, is a specific piece of DNA which gives a cell a specific
characteristics. For GE to be a possibility scientists had to break the genetic code.
Why GE?
Many scientists believe they can solve many food problems by
taking certain genes from plant or animal cells
and transfer them to other plants to change certain characteristics,
making the plant, say, more resistant to harmful insects.
Genetic engineering may seem like it holds particular promise for
crop-growers. With GE the desirable genes from one plant, animal or
microorganism can be put into an unrelated species, avoiding the
limitations of normal cross breeding. A wider range of traits
is available, and these traits can be incorporated more quickly
into target species than possible with conventional methods.
The idea at it's simplest level sounds great.
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The Genetic Code |
The Structure of DNA
The incredibly complex DNA molecule is made of many smaller units called
nucleotides. To put it simply, each nucleotide
is made of a part sugar (deoxyribose), part phosphate, and one
of four different bases - adenine (A), guanine (G), thymine (T) and
cytosine (C). Scientists now know
that DNA is formed from two strands of nucleotides, held together
by the
bonds between the bases on opposite strands. The DNA structure is
like
a ladder. The sides are formed by the sugar and phosphate groups and
the
rungs are the bases. The two strands forming the ladder are then twisted
to form the helix.
Proteins
These DNA molecules found in every living organism contain the
blueprint for all proteins made in a
cell. Each sequence of three bases along the DNA strand is a chemical
code
for one of the 20 amino acids - the building blocks of proteins.
To make the proteins, the DNA molecule is uncoiled, the strands
separate,
and the cell makes a copy of a particular gene, in the form of single-
stranded messenger RNA. The mRNA then moves to the cell's "factories"
called ribosomes, where it acts as a template for the manufacturing
of protein.
The code for the protein is read off the base sequence on the mRNA,
and
the appropriate amino acids are added to the protein one by one.
Solving the DNA Code
Scientists have known the complex amino acid sequence of many
proteins. Now that they have discovered which base sequences in DNA
were represented by which amino acids, they can identify the genes in
a cells DNA that create certain proteins - Proteins which are the
physical means by which cells have certain characteristics
The coding system is the same in all forms of life. A piece of DNA
from a mammal inserted
into the
DNA strand of a plant makes perfect sense to the plant cell.
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Recombinant DNA |
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The next step was to be able
to copy the desired gene and insert it into other cells. To do this,
scientists
used special enzymes, to break the DNA strand
at calculated points, insert new segments, and put the strand
back together again. The result, known as recombinant DNA, is DNA
that has extra genes, that in nearly all cases the cell would not have
ever had without the help of human technology.
So, What's Wrong?
The understanding scientists now have of the inner-workings of life on earth, through the understanding of DNA and the genetic code
is valuable knowledge that may lead to something great. However,
genetic engineering, taking genes from their
normal location in one organism and transferring them to a completely
different organism
or putting them back into the original organism a different combination, is what is bringing up so many important questions:
- Will inserting new DNA into an organism upset it's delicate life-sustaining balance?
- What exactly is GE used for, and how does it affect me?
- How precise is the cutting and pasting of genes?
- What are the short and long term effects of genetically engineered organisms on humans?
- How will GE effect the future of our food?
These questions and many more will be answered in the remainder of this site. Keep reading!
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