Why does DNA use thymine instead of uracil?
DNA uses thymine instead of uracil because thymine has greater resistance to photochemical mutation, making the genetic message more stable. Outside of the nucleus, thymine is quickly destroyed. Uracil is resistant to oxidation and is used in the RNA that must exist outside of the nucleus.
Why do we replace uracil in the RNA strand instead of thymine?
Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA. In DNA, however, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient.
Why is thymine used in DNA rather than uracil quizlet?
Spontaneous mutation of nucleotides – why doesn’t DNA use Uracil as a base? mostly due to the deamination of cytosine to uracil via hydrolysis-which releases ammonia. When thymine is used the cell can easily recognize that the uracil doesn’t belong there and can repair it by substituting it by a cytosine again.
How is thymine different from uracil?
Pyrimidine ring is a heterocyclic aromatic structure, which is made up of carbon and nitrogen atoms. Both chemical structures of uracil and thymine are very similar. They only differ by the presence of a methyl group in C-5 of thymine. Uracil only occurs in RNA while thymine only occurs in DNA.
Is thymine more stable than uracil?
Thymine at the place of uracil confers to additional stability because thymine has greater resistance to photochemical mutation, making the genetic material more stable. It also forms hydrogen bonds with adenine giving it extra stability.
What happens if uracil is in DNA?
Uracil from DNA can be removed by DNA repair enzymes with apirymidine site as an intermediate. However, if uracil is not removed from DNA a pair C:G in parental DNA can be changed into a T:A pair in the daughter DNA molecule. Therefore, uracil in DNA may lead to a mutation.
Why is the structure of DNA is more stable than that of RNA?
Due to its deoxyribose sugar, which contains one less oxygen-containing hydroxyl group, DNA is a more stable molecule than RNA, which is useful for a molecule which has the task of keeping genetic information safe.
Why is RNA less stable than DNA when most Phosphoesters are stable in water for millions of years?
Why is RNA less stable than DNA when most phosphoesters are stable in water for millions of years? You Answered RNA contains uracil. Ribose lacks a 2′ hydroxyl group.
Is uracil more stable than thymine?
What is the role of thymine in DNA?
In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures. Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine.
Why is uracil methylated to thymine?
In RNA, uracil base-pairs with adenine and replaces thymine during DNA transcription. Methylation of uracil produces thymine. In DNA, the evolutionary substitution of thymine for uracil may have increased DNA stability and improved the efficiency of DNA replication (discussed below).