Download PROTEIN MEMORY FOR COMPUTERS

PROTEIN MEMORY FOR COMPUTERS
Akshata.s.revankar
E&C,8thsem
Usn:2mm7ec002
Email:[email protected]
Abstract:
While magnetic and semi-conductor
based information storage devices
have been in use since the middle
1950's, today's computers and
volumes of information require
increasingly more efficient and faster
methods of storing data. While the
speed of integrated circuit random
access memory (RAM) has increased
steadily over the past ten to fifteen
years, the limits of these systems are
rapidly approaching. In response to
the rapidly changing face of
computing and demand for physically
smaller, greater capacity, bandwidth,
a number of alternative methods to
integrated circuit information storage
have surfaced recently. Among the
most promising of the new
alternatives are photopolymer-based
devices, holographic optical memory
storage devices, and protein-based
optical memory storage using
rhodopsin , photosynthetic reaction
centers, cytochrome c, photosystems I
and II, phycobiliproteins,
phytochrome.
and
Introduction:
This seminar focuses mainly on
protein-based optical memory storage
using the photosensitive protein
bacteriorhodopsin with the twophoton method of exciting the
molecules. Bacteriorhodopsin is a
light-harvesting protein from bacteria
that live in salt marshes that has
shown some promise as feasible
optical data storage. The current work
is to hybridize this biological
molecule with the solid state
components of a typical computer.
In response to the demand for
faster, more compact, and more
affordable memory storage devices,
several viable alternatives have
appeared in recent years. Among the
most promising approaches include
memory storage using holography,
polymer-based memory, and our
focus, protein-based memory.
What is protein memory?
Several biological molecules
are being considered for use in
computers, but the bacterial proteinBacteriorhodopsin (bR)-has generated
much interest among scientists. In the
past few decades, much research was
carried out in several laboratories in
North America, Europe, and Japan,
and the scientists become successful
in building prototype parallel
processing devices, three-dimensional
memories, and protein-based neural
networks.
Bacteriorhodopsin, a light
harvesting bacterial protein, is the
basic unit of protein memory and is
the key protein in halo bacterial
photosynthesis. It functions like a
light-driven photo pump. Under
exposure to light it transports photons
from the hollow bacterial cell to
another medium, changes its mode of
operation from photosynthesis to
respiration, and converts light energy
to chemical energy thus can be
utilized to frame protein memories.
ENERGY PATTERN
Protein Memory Chip
Advantages:
14. Advantages and Applications of
Bacteriorhodopsin
Bacteriorhodopsin
is
an
excellent molecule for photonics.
Naturally occurring, the purple
pigment grows in salt marshes and
has evolved to exist in half-a-dozen
stable states within a convenient,
reversible photo cycle. This robust
system, coupled with the emergence
of genetic engineering, forms the
basis of a variety of applications and
devices based on bacteriorhodopsin
that are now beginning to emerge.
The range of potential applications for
which bacteriorhodopsin (bR) has
been
Investigated is remarkable. It
includes:
1) Reversible holographic memory
2) Ultrafast random-access memory
3) Neural logic gates
4) Spatial light modulation
5) Nonlinear optical filters
6) Photonic-crystal band gap
materials,
7) Pattern-recognition systems
8) High-contrast displays
9) Optical switches
10) Pico second photo detectors.
Unlike
many
other
biomolecules, which are too unstable
to be used in any commercial device,
bR is protected against photo-induced
breakdown - which is caused by
reactive oxygen, singlet oxygen and
free radicals - by its structure.
15. Conclusion
Bacteriorhodopsin has attracted
the attention of scientists interested in
using biological materials to perform
technological functions. Part of the
attraction of natural materials is that
they often perform very complex
functions that cannot be easily
synthesized. Evolution has perfected
these functions over billions of years,
often performing better than humandesigned materials ever could.
In the last 25 years, bacteriorhodopsin
has excited a great deal of interest
among biochemists, biophysicists, and
most recently among companies
seeking to build battery conserving,
long-life computer displays. If
controllable, quick-change proteins
like bacteriorhodopsin could also be
used in a kind of electronic writing.
In addition, the protein's
photoelectric properties could be used
to manufacture Photo detectors.
Bacteriorhodopsin is also an attractive
material
for
all-optical
'light'
computers because of its two stable
protein forms, one purple and one
yellow. Shining two lasers of different
wavelengths alternately on the protein
flips it back and forth between the two
colors. Several research groups have
already used bacteriorhodopsin as
computer memory and as the lightsensitive element in artificial retinas.
With fast random access
capability, good reliability, and
transportability protein memories
enhance the multimedia capabilities
of computers to a great extent. Also,
the advantages of optical data storage
accrue to such memories. Enormous
access
to
information
and
manipulation and storage of data in
minimal time add to their reliability.
Unlike disk memories where physical
contact with the magnetic head is
required to Read/Write information,
protein memories use laser beams,
which improves their life with
reduction in wear and tear.
Researchers are now closely
following the way human brain stores,
retrieves, and acts on information, to
build a biological computer. They are
trying to duplicate the capability of
information retrieval by inputting a
part of it, or any related aspect,
instead of specifying the address of
the memory location. Though a group
of researchers headed by Robert Birge
of Suracuse University, USA, has
succeeded in developing similar ones,
much work is still required to make a
fully operational computer with
memory that mimics human brain.
Indeed, we are on the threshold
of new and exciting era in the
wonderful world of computing. And
every possibility is there that in the
near future we will be able to carry a
small encyclopedic cube containing
all the information we need
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