The Rochester team's DNA logic gates are the first step
toward creating a computer that has a structure similar to that of an
electronic PC. Instead of using electrical signals to perform logical
operations, these DNA logic gates rely on DNA code. They detect fragments of
genetic material as input, splice together these fragments and form a single
output. For instance, a genetic gate called the "And gate" links two
DNA inputs by chemically binding them so they're locked in an end-to-end
structure, similar to the way two Legos might be fastened by a third Lego
between them. The researchers believe that these logic gates might be combined
with DNA microchips to create a breakthrough in DNA computing.
DNA computer components -- logic gates and biochips -- will
take years to develop into a practical, workable DNA computer. If such a
computer is ever built, scientists say that it will be more compact, accurate
and efficient than conventional computers. In the next section, we'll look at
how DNA computers could surpass their silicon-based predecessors, and what
tasks these computers would perform.
Surpassing Silicon?
Although DNA computers haven't overtaken silicon-based
microprocessors, researchers have made some progress in using genetic code for
computation. In 2003, Israeli scientists demonstrated a limited, but
functioning, DNA computer. You can read more about it at National Geographic.
Silicon microprocessors have been the heart of the computing
world for more than 40 years. In that time, manufacturers have crammed more and
more electronic devices onto their microprocessors. In accordance with Moore's
Law, the number of electronic devices put on a microprocessor has doubled every
18 months. Moore's Law is named after Intel founder Gordon Moore, who predicted
in 1965 that microprocessors would double in complexity every two years. Many
have predicted that Moore's Law will soon reach its end, because of the
physical speed and miniaturization limitations of silicon microprocessors.
DNA computers have the potential to take computing to new
levels, picking up where Moore's Law leaves off. There are several advantages
to using DNA instead of silicon:
As long as there are cellular organisms, there will always
be a supply of DNA.
The large supply of DNA makes it a cheap resource.
Unlike the toxic materials used to make traditional
microprocessors, DNA biochips can be made cleanly.
DNA computers are many times smaller than today's computers.
DNA's key advantage is that it will make computers smaller
than any computer that has come before them, while at the same time holding
more data. One pound of DNA has the capacity to store more information than all
the electronic computers ever built; and the computing power of a
teardrop-sized DNA computer, using the DNA logic gates, will be more powerful
than the world's most powerful supercomputer. More than 10 trillion DNA
molecules can fit into an area no larger than 1 cubic centimeter (0.06 cubic inches).
With this small amount of DNA, a computer would be able to hold 10 terabytes of
data, and perform 10 trillion calculations at a time. By adding more DNA, more
calculations could be performed.
Unlike conventional computers, DNA computers perform calculations
parallel to other calculations. Conventional computers operate linearly, taking
on tasks one at a time. It is parallel computing that allows DNA to solve
complex mathematical problems in hours, whereas it might take electrical
computers hundreds of years to complete them.
The first DNA computers are unlikely to feature word
processing, e-mailing and solitaire programs. Instead, their powerful computing
power will be used by national governments for cracking secret codes, or by
airlines wanting to map more efficient routes. Studying DNA computers may also
lead us to a better understanding of a more complex computer -- the human
brain.
Source" http://computer.howstuffworks.com/dna-computer2.htm "
Source" http://computer.howstuffworks.com/dna-computer2.htm "
