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)
Uracil is present in RNA but not in DNA. DNA contains thymine instead of uracil.
Uracil is not naturally present in DNA. Instead, it is found in RNA, where it replaces the thymine base found in DNA. Thymine is the corresponding base in DNA and is not found in RNA.
Thymine
Uracil is the base that is a component of RNA only. Thymine is found in DNA, while adenine, cytosine, and guanine are present in both RNA and DNA.
A nitrogenous base called uracil is found in RNA but not in DNA. Conversely, DNA contains the nitrogenous base thymine, which is absent in RNA.
Uracil is present in RNA but not in DNA. DNA contains thymine instead of uracil.
RNA has the base uracil rather than thymine that is present in DNA, so the answer to you question is.. thymine.
uracil
Uracil is not naturally present in DNA. Instead, it is found in RNA, where it replaces the thymine base found in DNA. Thymine is the corresponding base in DNA and is not found in RNA.
Uracil. Uracil is not present in DNA, but it is present in RNA. DNA's "equivalent" base is thymine, meaning when DNA is transcribed into RNA, the places where thymine would go instead has uracil.
Thymine
Uracil is the pyrimidine base found in RNA that is not present in DNA. Uracil pairs with adenine in RNA during transcription and translation processes.
Thymine is a nucleobase found in DNA, but it is not present in RNA. In RNA, thymine is replaced by uracil.
4 NITROGEN BASIS OF DNA:ADENINE GUANINECYTOSINETHYMINEIN RNA, Thymine changes to Uracil.
The nitrogen base uracil is not present in DNA. It is only present in RNA and is used as a substitute for thymine
Uracil is the base that is a component of RNA only. Thymine is found in DNA, while adenine, cytosine, and guanine are present in both RNA and DNA.
Uracil is in RNA and Thyramine is in DNA, the other nitrogen bases are the same In RNA Adenine is complementary to Uracil and Guanine is complementary to cytocine In DNA Adenine is complementarty to Tyramine and Guanine is complentary to cytocine