11-10-2010, 09:38 AM
PROTEIN MEMORIES.doc (Size: 57 KB / Downloads: 132)
INTRODUCTION
Molecular electronics is an emerging field that lies at the interface of chemical physics, electrical engineering and solid state science. It involves encoding, manipulation and retrieval of information at the macromolecular level in contrast to current techniques which are fast approaching their practical limits.
Molecular electronics provides new methodologies for high speed signal processing, holographic associate memories and 3D optical memories. Molecular devices are reliable and competitive with semiconductor devices when monomolecular state assignment averaging can be implemented. Biomolecular electronics offers significant promise in addressing some of the inherent limitations of semiconductor architecture.
BIOMOLECULAR COMPUTERS
Is a computer based on the dynamics of bio molecular activities rather than on electronic switching. By exploiting some special properties of biological molecules, particularly proteins, components that are smaller, faster and more powerful than any electronic device can be made to function.
Since 1960’s the computer industry has been compelled to make the individual components on semiconductor chips smaller and smaller inorder to manufacture large memories and more powerful processors economically. These chips consists of array of switches, usually of the kind known as logical gates that flip between two states-0 or 1 in response to electric current passing through them. If the trends toward miniaturization continues, the size of single logic gate will approach the size of molecules in the year 2030.
A serious roadblock to miniaturization is the increase in cost of manufacturing a chip. At some point the search for even smaller electronic devices may be limited by economics rather than physics. So the use of biological molecules as the active components in computer circuitry may offer an alternative approach that is more economical.
Molecules can potentially serve as computers switches because their atoms are mobile and change position in a predictable way. If we can direct the atomic motion and thereby constantly generate two discrete states in a molecule, we can use each state to represent either 0 or 1.This results in reduction of size, that is, a biomolecular computer in principle is one-fifth of the size of the present day semiconductor computer. This theoretically makes it thousand times modern computers.
Researchers have introduced parallel processing architecture which allows multiple rows of data to be manipulated simultaneously. In order to expand memory capacities, they are devising hardware that stores data in 3D instead of usual ways. So scientists have built nueral networks that mimic the leasing by association capabilities of the brain. The ability of creating proteins to change their properties in response to light should simplify the hardware required for its implementations.
Although no computer components made from proteins are in the market yet, ongoing international research efforts are making enticing headway. Several molecules are under consideration for the use in computers. Bacteriorhodopsin has generated the most interest.
ORIGIN IN SALT MARSH
Bacteriorhodopsin is a light harvesting protein in the purple membrane of a micro organism called Halobacterium halobium .Bacterior-hodopsin , the bacterial protein , is the basic unit of protein memory and is the key protein in Halobacterial photosynthesis .It functions like a light –driven photo pump. Under exposure to light it transports photons from the halobacterial cell to another medium, changes its mode of operation from photosynthesis to respiration, and converts light energy to chemical energy. The response of this molecule to light energy can be utilised to frame prutein memories.
Bacteriorhodopsin grows in salt marshes ,where temperature can exceed 150 degree F for the extended time period and the salt concentration is approximately six times that of sea water. Survival in such an environment implies that this protein can resist thermal and photochemical damages. Upon absorption of light it generates a chemical and osmotic potential that serves as energy source. It has the ability to form thin films that exhibit excellent optical characteristics and offer long term stability .
ORIGIN IN SALT MARSH
Bacteriorhodopsin is a light harvesting protein in the purple membrane of a micro organism called Halobacterium halobium .Bacterior-hodopsin , the bacterial protein , is the basic unit of protein memory and is the key protein in Halobacterial photosynthesis .It functions like a light –driven photo pump. Under exposure to light it transports photons from the halobacterial cell to another medium, changes its mode of operation from photosynthesis to respiration, and converts light energy to chemical energy. The response of this molecule to light energy can be utilised to frame prutein memories.
Bacteriorhodopsin grows in salt marshes ,where temperature can exceed 150 degree F for the extended time period and the salt concentration is approximately six times that of sea water. Survival in such an environment implies that this protein can resist thermal and photochemical damages. Upon absorption of light it generates a chemical and osmotic potential that serves as energy source. It has the ability to form thin films that exhibit excellent optical characteristics and offer long term stability .