How DNA works

            Like the ring of power in Tolkien's "Lord of the Rings," deoxyribonucleic acid (DNA) is the master molecule of every cell. It contains vital information that gets passed on to each successive generation. It coordinates the making of itself as well as other molecules (proteins). If it is changed slightly, serious consequences may result. If it is destroyed beyond repair, the cell dies.
            Changes in the DNA of cells in multicellular organisms produce variations in the characteristics of a species. Over long periods of time, natural choice acts on these variations to evolve or alter the species.
The presence or absence of DNA facts at a crime scene could mean the difference between a guilty verdict & an acquittal. DNA is so important that the United States government has spent immense amounts of money to unravel the sequence of DNA in the human genome in hopes of understanding & finding cures for plenty of genetic diseases. Finally, from the DNA of cell, they can clone an animal, a plant or perhaps even a human being.
             But what is DNA? Where is it found? What makes it so special? How does it work? In this editorial, they will look deep in to the structure of DNA & report the way it makes itself & the way it determines all of your traits. First, let's look at how DNA was discovered.
             DNA is of a class of molecules called nucleic acids. Nucleic acids were originally discovered in 1868 by Friedrich Meischer, a Swiss biologist, who isolated DNA from pus cells on bandages. Although Meischer suspected that nucleic acids might contain genetic information, he could not confirm it.
So scientists had theorized about the informational role of DNA for a long time, but nobody knew how this information was encoded & transmitted. Plenty of scientists guessed that the structure of the molecule was important to this technique. In 1953, James D. Watson & Francis Crick discovered the structure of DNA at Cambridge University. The story was described in James Watson's book "The Double Helix" & brought to the screen in the film, "The Race for the Double Helix." Fundamentally, Watson & Crick used molecular modeling techniques & information from other investigators (including Maurice Wilkins, Rosalind Franklin, Erwin Chargaff & Linus Pauling) to solve the structure of DNA. Watson, Crick & Wilkins received the Nobel Prize in Medicine for the discovery of DNA's structure (Franklin, who was Wilkins' collaborator & provided a key piece of information that exposed the structure to Watson & Crick, died before the prize was awarded).
            In 1943, Oswald Avery & colleagues at Rockefeller University showed that DNA taken from a bacterium, Streptococcus pneumonia, could make non-infectious bacteria become infectious. These results indicated that DNA was the information-containing molecule in the cell. The information role of DNA was further supported in 1952 when Alfred Hershey & Martha Chase demonstrated that to make new viruses, a bacteriophage virus injected DNA, not protein, in to the host cell.

Silicon vs. DNA Microprocessors

• Silicon microprocessors have been the heart of the computing world for over 40 years. In that time, manufacturers have crammed increasingly 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 years. Plenty of have predicted that Moore's Law will soon reach its finish, because of the physical speed & 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's several advantages to using DNA in lieu of silicon:
• As long as there's cellular organisms, there will always be a supply of DNA.The giant supply of DNA makes it an affordable resource.
• Unlike the poisonous materials used to make traditional microprocessors, DNA biochips can be made cleanly.
• DNA computers are plenty of 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 simultaneously holding more information. pound of DNA has the capacity to store more information than all the electronic computers ever built & 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. Over ten trillion DNA molecules can fit in to an area no larger than one cubic centimeter (0.06 cubic inches). With this small amount of DNA, a computer would be able to hold ten terabytes of information, & perform ten 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 separately. It is parallel computing that allows DNA to solve complex mathematical issues 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 & solitaire programs. In lieu, their powerful computing power will be used by national governments for cracking secret codes, or by airlines desirous to map more efficient routes. Studying DNA computers may also lead us to a better understanding of a more complex computer -- the human brain.

Success of the Adleman DNA computer

             The success of the Adleman DNA computer proves that DNA can be used to calculate complex mathematical issues. However, this early DNA computer is far from challenging silicon-based computers in terms of speed. The Adleman DNA computer created a group of feasible answers very quickly, but it took days for Adleman to narrow down the possibilities. Another drawback of his DNA computer is that it requires human assistance. The objective of the DNA computing field is to generate a device that can work independent of human involvement.

Years after Adleman's experiment, researchers at the University of Rochester developed logic gates made of DNA. Logic gates are a vital part of how your computer carries out functions that you command it to do. These gates convert binary code moving through the computer in to a series of signals that the computer makes use of to perform operations. Currently, logic gates interpret input signals from silicon transistors, and convert those signals in to an output signal that allows the computer to perform complex functions.

The Rochester team's DNA logic gates are the first step toward making a computer that has a structure similar to that of an electronic PC. In lieu of using electrical signals to perform logical operations, these DNA logic gates depend on DNA code. They detect fragments of genetic material as input, splice together these fragments and form a single output. For example, a genetic gate called the "And gate" links DNA inputs by chemically binding them so they are locked in an end-to-end structure, similar to the way Legos might be fastened by a third Lego between them. The researchers think that these logic gates might be combined with DNA microchips to generate a breakthrough in DNA computing.

DNA computer parts -- logic gates and biochips -- will take years to create in to a practical, workable DNA computer. If such a computer is ever built, scientists say that it will be more compact, correct 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.

DNA computing technology

                 DNA computers cannot be found at your local electronics store yet. The know-how is still in development, and didn't even exist as an idea a decade ago. In 1994, Leonard Adleman introduced the idea of using DNA to solve complex mathematical issues. Adleman, a computer scientist at the University of Southern New york, came to the conclusion that DNA had computational potential after reading the book "Molecular Biology of the Gene," written by James Watson , who co-discovered the structure of DNA in 1953. In fact, DNA is similar to a computer hard drive in the way it stores permanent information about your genes.

                 Adleman is often called the inventor of DNA computers. His editorial in a 1994 issue of the journal Science outlined how to make use of DNA to solve a widely known mathematical issue, called the directed Hamilton Path issue, often known as the "traveling salesman" issue. The objective of the issue is to find the shortest route between lots of cities, going through each city only three times. As you add more cities to the issue, the issue becomes more difficult. Adleman chosen to find the shortest route between three cities.

You could probably draw this issue out on paper and come to a solution faster than Adleman did using his DNA test-tube computer.

Here are the steps taken in the Adleman DNA computer experiment :
         1.  Strands of DNA represent the three cities. In genes, genetic coding is represented by the letters A, T, C and G. Some sequence of these letters represented each city and feasible flight path.
         2.  These molecules are then mixed in a check tube, with some of these DNA strands sticking together. A chain of these strands represents a feasible answer.
         3.  Within a few seconds, all of the feasible combinations of DNA strands, which represent answers, are created in the check tube
         4.  Adleman eliminates the wrong molecules through chemical reactions, which leaves behind only the flight paths that connect all three cities.

How DNA computer's will work

               While still in their infancy, DNA computers will be able to storing billions of times more information than your personal computer. In this news story, you'll learn how scientists are using genetic material to generate nano-computers that might take the place of silicon-based computers in the next decade.

Even as you read this news story, computer chip manufacturers are furiously racing to make the next microprocessor that will topple speed records. Ultimately, though, this competition is bound to hit a wall. Microprocessors made of silicon will finally reach their limits of speed & miniaturization. Chip makers need a new material to produce faster computing speeds.

You won't think where scientists have found the new material they need to build the next generation of microprocessors. Millions of natural supercomputers exist inside living organisms, including your body. DNA (deoxyribonucleic acid) molecules, the material our genes are made of, have the potential to perform calculations plenty of times faster than the world's most powerful human-built computers. DNA might day be integrated in to a computer chip to generate a so-called biochip that will push computers even faster. DNA molecules have already been harnessed to perform complex mathematical issues.

DNA REPAIR

                DNA Repair provides a forum for the comprehensive coverage of cellular responses to DNA destroy in living cells. The journal publishes original observations on genetic, cellular, biochemical & molecular aspects of  DNA repair, mutagenesis, cell cycle regulation, apoptosis & other biological responses to cells exposed to genomic insult, as well as their relationship to human diseases.

                DNA Repair publishes Full-length research papers, Brief Document of Research, Invited minireviews, Letters to the Editor, Hot topics in DNA repair, Classics in DNA repair, Historical reflections, Book reviews & Meeting Reports. DNA Repair also welcomes Correspondence from the scientific community, as they relate to papers historically in the past published in the journal. These are handled directly by the Editor-in-Chief & may be accompanied by responses solicited papers are published every month. In addition, the journal will publish a smaller number of peer-reviewed Brief Reports on original research findings of special interest, as well as invited Mini-reviews on chosen topics that provide 'state-of-the-art' synopses of cellular responses to DNA destroy. Book reviews & meeting reports will be regularly featured & the Journal welcomes Correspondence from the scientific community, as they relate to papers historicallyin the past published in the journal. These are handled directly by the Editor-in-Chief & may be accompanied by responses solicited from relevant individuals.

BASIC RESEARCH ON DNA

Gregor Mendel
   ~~>  Gregor Mendel the "Father of Genetics" performed an experiement in 1857 that led to increased interest in the study of genetics. Mendel who became a monk of the Roman Catholic church in 1843, studied at the University of Vienna where he mastered arithmetic, & then later performed lots of scientific experiments. The greatest experiment that Mendel performed involved growing thousands of pea plants for 8 years. He was made to give up his experiment when he became abbot of the monastery because of the political issues of the time. He died in 1884, but has been recalled for the great contribution to science that he made. To learn about his experiment & what it led to read: Genetics.

Frederick Griffith
  ~~>   In 1928 a scientist named Frederick Griffith was working on a project that enabled others to point out that DNA was the molecule of inheritance. Griffith's experiment involved mice & types of pneumonia, a virulent as well as a non-virulent kind. He injected the virulent pneumonia in to a mouse & the mouse died. Next he injected the non-virulent pneumonia in to a mouse & the mouse continued to live. After this, he heated up the virulent disease to kill it & then injected it in to a mouse. The mouse lived on. Last he injected non-virulent pneumonia & virulent pneumonia, that had been heated & killed, in to a mouse. This mouse died.

•   Why? Griffith thought that the killed virulent bacteria had passed on a characteristic to the non-virulent to make it virulent. He thought that this characteristic was in the inheritance molecule. This passing on of the inheritance molecule was what he called transformation.