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DNA methylation essentially causes DNA to stick to the histones. RNA polymerase, an enzyme that splits DNA apart for transcription, cannot access methylated DNA, so it isn't used in protein synthesis. It is effectively silenced by the attached methyl group.
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Why uracil is present in RNA and not in DNA?
methylation protects the DNA. Beside using dT instead of dU, most organisms also use various enzymes to modify DNA after it has been synthesized. Two such enzymes, dam and dcmmethylate adenines and cytosines, respectively, along the entire DNA strand. This methylation makes the DNA unrecognizable to many Nucleases (enzymes which break down DNA and RNA), so that it cannot be easily attacked by invaders, like viruses or certain bacteria. Obviously, methylating the nucleotides before they are incorporated ensures that the entire strand of DNA is protected. Thymine also protects the DNA in another way. If you look at the components of nucleic acids, phosphates, sugars, and bases, you see that they are all very hydrophilic (water soluble). Obviously, adding a hydrophobic (water insoluble) methyl group to part of the DNA is going to change the characteristics of the molecule. The major effect is that the methyl group will be repelled by the rest of the DNA, moving it to a fixed position in the major groove of the helix. This solves an important problem with uracil - though it prefers adenine, uracil can base-pair with almost any other base, including itself, depending on how it situates itself in the helix. By tacking it down to a single conformation, the methyl group restricts uracil (thymine) to pairing only with adenine. This greatly improves the efficiency of DNA replication, by reducing the rate of mismatches, and thus mutations. To sum up: the replacement of thymine for uracil in DNA protects the DNA from attack and maintains the fidelity of DNA replication. Sunil Nagpal B.tech(h)Biotechnology 2nd year LPU-Jalandhar(punjab)(INDIA)
What checks DNA for error?
DNA fingerprinting
Principle enzyme involved in DNA replication?
DNA Polymerase.
What is the function of DNA helicare in DNA replication?
DNA Helicase unwinds and unzips the DNA. It separates the two strands of DNA so DNA replication can occur.
A biologist is studying the process of how DNA is copied study which one DNA transcription DNA elongation DNA translocation DNA polymerase DNA replication?
o
How do microbes protect themselves from other microbes?
They proctect themselfs by methylating their DNA and by using their restriction enzymes.
Why uracil is present in RNA and not in DNA?
methylation protects the DNA. Beside using dT instead of dU, most organisms also use various enzymes to modify DNA after it has been synthesized. Two such enzymes, dam and dcmmethylate adenines and cytosines, respectively, along the entire DNA strand. This methylation makes the DNA unrecognizable to many Nucleases (enzymes which break down DNA and RNA), so that it cannot be easily attacked by invaders, like viruses or certain bacteria. Obviously, methylating the nucleotides before they are incorporated ensures that the entire strand of DNA is protected. Thymine also protects the DNA in another way. If you look at the components of nucleic acids, phosphates, sugars, and bases, you see that they are all very hydrophilic (water soluble). Obviously, adding a hydrophobic (water insoluble) methyl group to part of the DNA is going to change the characteristics of the molecule. The major effect is that the methyl group will be repelled by the rest of the DNA, moving it to a fixed position in the major groove of the helix. This solves an important problem with uracil - though it prefers adenine, uracil can base-pair with almost any other base, including itself, depending on how it situates itself in the helix. By tacking it down to a single conformation, the methyl group restricts uracil (thymine) to pairing only with adenine. This greatly improves the efficiency of DNA replication, by reducing the rate of mismatches, and thus mutations. To sum up: the replacement of thymine for uracil in DNA protects the DNA from attack and maintains the fidelity of DNA replication. Sunil Nagpal B.tech(h)Biotechnology 2nd year LPU-Jalandhar(punjab)(INDIA)
How is DNA tested and why?
by DNA fingerprinting method , DNA-DNA hybirdization or DNA sequencing. to know the sequence of DNA
What is producing the characteristic helix shape of the DNA?
Physics. It's kind of difficult to be more specific than that, because there really isn't one single thing that causes it. It has to do with hydrogen bond formation, characteristic bond lengths and angles, the relative repulsion of highly charged ions, overlap of the pi clouds in the aromatic rings of the bases ... the double helix manages to satisfy all those conditions while creating a local minimum in the energy. Now, there could be other shapes that satisfy the conditions -- in fact, there are at least three known naturally occuring helix forms that do so; these are called A-DNA (which adds a bit of a curve to the helix itself and is found particularly in dehydrated samples), B-DNA (the "normal" one), and Z-DNA (which twists the other way). For that matter, there are over 20 known forms, most of which only occur in the laboratory with a bit of artificial "prodding" such as methylating certain sites in the molecule.
What checks DNA for error?
DNA fingerprinting
How do you produce DMT?
The pineal gland produces DMT naturally, most probably by doubly methylating thyptophan, a naturally occurring amino acid. Plants probably do it the same way as well. WikiAnswers does not promote illegal acts, so we can't tell you how to extract or isolate it.
How would the DNA of the human compare to the DNA of the duck?
DNA is DNA it can not be changed.
Principle enzyme involved in DNA replication?
DNA Polymerase.
What is a DNA molecule containing regions from different sources?
Chimeras. In genetic engineering, molecules of combined DNA are known as chimeras because they are produced by combining DNA from different species. Combined DNA is also known as recombinant DNA, since DNA from 2 sources has been recombined to produce it.
What enzyme binds fragments of DNA on the lagging strand?
The enzyme that is used to bind DNA fragments together is DNA ligase. Using DNA ligase to join DNA fragments is the last step in the production of a recombinant DNA plasmid.
What is the function of DNA helicare in DNA replication?
DNA Helicase unwinds and unzips the DNA. It separates the two strands of DNA so DNA replication can occur.
A biologist is studying the process of how DNA is copied study which one DNA transcription DNA elongation DNA translocation DNA polymerase DNA replication?
o
