In nucleic acids each nucleotide has one phosphate group attached. .
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The Arrangement Of Components.
X-Ray Diffraction.
During the 1940's and 1950's scientists were using X-Ray Diffraction to look at the structure of protein. In X-Ray diffraction X-Rays are directed at crystal of the substance studied. The X-Rays are diffracted by the crystal, and the patterns they make give a skilled scientist, armed with a computer, information about the positions of atoms in the molecule. .
Once DNA had been identified, as the genetic material scientists were keen to use the same technique to study at DNA. This was not easy because DNA was difficult to crystallise. Two of the scientists who succeeded in overcoming the technical difficulties were Rosalind Franklin and Maurice Wilkins. Wilkins was the first to obtain crystals of pure DNA but these were crystals of the A form of DNA: this structure formed when little water is present. In contrast, Franklin worked on crystals of the B form: this is the structure that DNA forms when more water is present. Both scientists showed that DNA was a helix. It is the B form of DNA that proved to be more biologically important.
Meanwhile James Watson and Francis Crick were working with atomic models at Cambridge. Not much was achieved until Watson went to Kings College to have a look at the picture taken by Rosalind Franklin. When Watson returned they began to work intensely on the project. Soon Watson came up with the final piece of the puzzle, the base pairing system of A, T, G and C. Watson realized that if A paired with T, and G paired with C, the two pairs had the same shape and would be held together nicely by hydrogen bonds. He was able to fit the bases into a double standard phosphate sugar backbone helix with phosphate sugar backbone on the outside. Below is a picture of James Watson (left) and Francis Crick with their model of the DNA molecule.
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One scientist, Erwin Chargraff, set out to prove that DNA was a more complex molecule than had first been thought, a molecule that was worthy to be the genetic material.
Some viruses do not have DNA, but contain RNA instead. ... (Heath, 110) DNA can also be found outside of chromosomes. ... DNA contains four nitrogenous bases. ... The new DNA strand stays attached to the old one through the hydrogen bonds, and together they form a new DNA double helix molecule. ... RNA molecules are like DNA. ...
DNA is a big step for science. Yet many people don't know the purpose of DNA and what it really can do, but DNA is actually a big thing. ... DNA also contains much more personal information than a fingerprint. ... They could also destroy years of investigation by destroying the DNA-files. ... A DNA profile is a string of numbers stored on a computer. ...
The DNA molecule, itself, is safely kept inside the cells nucleus. ... When the cell multiplies into other cells, the DNA has to be "photocopied." ... The two main scientists who discovered the double helix of DNA are James Watso and Francis Crick. ... He was a biochemist and Nobel Prize winner, who helped determine the structure of DNA today. ... In 1953 he and James Watson discovered the secret to life, the double helix of DNA. ...
DNA fingerprinting has many advantages and disadvantages. ... What if DNA fingerprinting also helped reduce crime? ... To an extent, no two people have the same DNA sequence. DNA is also durable. ... As mentioned earlier, not all courts accept DNA fingerprin...
DNA I am going to write about if Law Enforcement should team up with doctors to try and make society a safer and better place. ... Look at the potential DNA has to offer in solving a crime it is unbelievable. ... There is nothing wrong with taking DNA from a criminal and keeping it on record, even if it's from just a violent offender. ... Next I would like to put my emphasis on how good of an idea it is to take DNA from a newborn, unlike Mary Faith. What's wrong with taking DNA from a newborn and keeping a database, maybe and hopefully, it could deter and slow down crime in the Uni...
DNA Testing DNA technology has provided law enforcement officers and investigators with a way to solve many crimes that would have previously been unsolvable. DNA technology has improved the way we solve crimes. ... DNA is similar to fingerprint analysis because every person's DNA is different. When DNA is found at a crime scene it is compared to DNA that is already on file to determine if it is a match, much like if it were a fingerprint. ... Without DNA testing hundreds of criminals would be free. ...
However there are many disadvantages to DNA testing, such as a challenge of accuracy, the costs of DNA testing and the possible misuse of DNA. ... However many people disagree to the use of DNA results. Many question the accuracy of DNA evidence, as only DNA segments are used in databases in contrast to the entire DNA strand. ... DNA testing is also very expensive, and the accused might not be able to afford a DNA expert to defend him or herself in court if DNA evidence is used against them, and if DNA experts are hired for them, there is a possibility of bias. ... Victoria has had a DNA datab...
DNA Fingerprinting: Guilty or Innocent? ... DNA tests also work with sites in DNA that have different lengths because of their variable numbers of repeated units (VNTRs) (Housman 543). ... This procedure, called "amplification," which uses DNA polymerase to create exact copies of fragment of DNA in a test tube at very high rates, reaches a result in several hours ("DNA Identification" 4). ... Technology's first legal test on DNA took place in 1987. ... "DNA tests can absolutely eliminate someone," says L.A. public defender Walter Krustjla, who is a DNA chemist as well as a lawyer ...
The Drawback of DNA Evidence Outline I. Introduction a. Definition of Evidence b. Three Ways to Solve a Crime c. Thesis II. A Mistaken DNA Identification? What Does It Mean? a. The Odds of Having Similar DNA b. Outcome of the Case III. Other Point of Views from Experts a. Views fro...
Cole Cuchna Per 3 Molecule of the Month: DNA The "thread of life", is deoxyribonucleic acid, otherwise known as DNA. ... DNA can be manipulated to change all kinds of things. ... DNA is damaged by exposure to ultraviolet (UV) light. The DNA does have the ability to repair it self, however. DNA can also be used to match suspects in a crime. ...
