When did RNA become DNA?
When did RNA become DNA?
around 4 billion years ago
Why DNA is stable than 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. RNA, containing a ribose sugar, is more reactive than DNA and is not stable in alkaline conditions.
Is DNA or RNA less reactive?
RNA is more reactive than DNA because of the ribose units in its structure, which have a highly reactive hydroxyl group on C2 that takes part in RNA-mediated enzymatic events. RNA is single-stranded, while DNA is mostly double-stranded. RNA has larger grooves than DNA, which makes it easier to be attacked by enzymes.
Why is RNA very reactive?
Due to the presence of –OH group in the ribose sugar, it is more active. Also, the nitrogenous base is hydrophobic whereas the sugar end and the phosphoric acid end present in both RNA & DNA is hydrophilic. But RNA is single stranded, hence its nitrogenous base is not away from water, and thus is reactive.
Why is uracil more reactive than thymine?
There are many explanations for that: 1. Despite uracil’s tendency to pair with adenine, it can also pair with any other base, including itself. So using thymine instead makes it way easier and more stable, as any uracil inside DNA must come from a cytosine and so it can be replaced by a new cytosine.
Why is U not used in DNA?
Explanation: 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.
Is uracil more stable than thymine?
So using thymine instead makes it way easier and more stable, as any uracil inside DNA must come from a cytosine and so it can be replaced by a new cytosine.
Why is u used instead of T in RNA?
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.
What does RNA contain that DNA does not?
It differs from DNA chemically in two respects: (1) the nucleotides in RNA are ribonucleotides—that is, they contain the sugar ribose (hence the name ribonucleic acid) rather than deoxyribose; (2) although, like DNA, RNA contains the bases adenine (A), guanine (G), and cytosine (C), it contains the base uracil (U) …