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DNA
- desoxyribonucleic acid
The
so-called DNA structure was discovered in 1953.
What
does that mean?
Each living matter consists of a multitude of cells. Each of these
cells has a nucleus that contains the hereditary pattern. It is possible
to analyze the tiniest details of an organism or even to manipulate
the hereditary pattern with the help of that organism's DNA structure.
An exact identification of living matter is possible with the analysis.
In future, the world of electronics will notice more frequent encounters
with the abbreviation "DNA." Scientists are even developing DNA computers
at this time.
Discovery:
During the first half of the 20th century, science mainly dealt with
nuclear physics. Those early scientists were involved in the attempt
to decode the secrets of the atom and to research the smallest parts
of the universe.
Two
scientists, James Watson and Francis Crick, discovered the DNA structure
and thus established a new branch of science known as molecular biology
in 1953. With the help of molecular biology, Watson and Crick made
the research of the latest mysteries of life and the nearly boundless
manipulation of those mysteries possible. Cloning genes, gene banks
and genetic identification was entirely inconceivable three decades
ago. In the future, thanks to the discovery of DNA, many illnesses
may be cured or prevented. Certainly this knowledge may also have
disastrous consequences in the wrong hands.
The
structure of a cell:
Cells are the foundation of all living matter. Most of them are tiny
structures with only few thousandth of a millimeter in diameter.
The
human body consists of about 100,000 billion cells. These cells can
just be imagined as simple, small bags filled with different vital
substances such as proteins, nucleic acids, fats and carbohydrates,
necessary for different aspects of life. In the interior of the cell
there can be found one of the most important parts – the nucleus,
without which the cell couldn't exist. The hereditary pattern is contained
here in chromosomes.
These
cellular components contain the genes that consist of deoxyribonucleic
acid (DNA). In a human germ cell there are 23 chromosomes; each of
them contains about 100,000 genes.

The
DNA structure:
DNA has two essential properties: It stores the information needed
to build or to maintain a living matter and it can replicate itself.
The DNA molecule is actually very long, although it is altogether
much too small to be seen in an optical microscope. Its structure
suggests that of a twisted rope ladder with millions of rungs. In
the DNA there are only four bases: adenine (A), thymine (T), cytosine
(C) and guanine (G). The rungs consists of two bases per rung (either
A and T or G and C). When a DNA cord splits like a zip lengthwise,
the missing half on either side always completes a new DNA strand
by corresponding to the old building plan. The two newly built double-stranded
cords look exactly like the original one in their succession of bases.
Identical cells are produced through this cell division.
Genetic
identification:
Closely related people have similar DNA band patterns, while unrelated
people have different ones. The individual bands correspond to the
so-called cell sequences in the DNA. Through radiation the bands are
exposed onto a film, in a process known as gel electrophoresis.
Such
genetic fingerprints that result from the patterning of DNA bands
can be used for affiliation proceedings and for forensic medicine.
Only a small sample of blood, sperm or any other body tissue, such
as a hair, for example, is needed.
Combating
crime through DNA fingerprints began in England in 1987. To track
down a murderer, blood samples were taken from about 5000 men.
Future:
The problem of many computer users is that greater storage capacity
is increasingly necessary. Scientists are developing a DNA computer
following the biological model of the DNA molecule. Such a computer
would have enormous advantages, low energy consumption, and extremely
high storage density. One single cubic centimeter of DNA liquid would
be able to store up to a trillion giga bits. Do the math... Wow!
