Asked by: Cenaida Schafernichtscience genetics
Why do hydrogen bonds form between purines and pyrimidines?
Last Updated: 23rd May, 2020
Click to see full answer.
Similarly, why does a pyrimidine only bond with a purine?
The molecular structure of both pyrimidinesandpurines allow them to only be able tobondwith each other and not within the group.Thymine(pyrimidine)and adenine (purine) both have twoatomsthat can either provide a H bond or receive it.Cytosine(pyr.) and guanine (pur.) can stablish threeHbonds.
Beside above, what type of bonds form between purines and pyrimidines? Purines always bond withpyrimidinesvia hydrogen bonds following the Chargaffrule in dsDNA, morespecifically each bond followsWatson-Crick base pairingrules. Therefore adenine specificallybonds to thymineforming two hydrogen bonds, whereasguanine formsthree hydrogen bonds withCytosine.
Consequently, why do purines bond with pyrimidines in DNA?
Purines (adenine and guanine) have twocarbonnitrogen ring bases. I think purines bond withpyrimidinesin the DNA ladder because adenine moleculesonly pairthymine molecules and guanine molecules only pair withcytosinemolecules. A and T bond with 2 hydrogen bonds, C andGbond with 3 hydrogen bonds.
Why there is double bond between adenine and thymine?
In the DNA helix, the bases: adenine,cytosine,thymine and guanine are each linked withtheircomplementary base by hydrogen bonding.Adenine pairswith thymine with 2 hydrogenbonds. This differencein strength is because of thedifference in the number of hydrogenbonds.