Maybe this is a silly question, but I just wanna know, why DNA is formed in twisted double helix? Why not just straight like RNA? Thanks for helping. I find this forum has assisted me much in doing school tasks… 😀
evolution, DNA is more stable that way then RNA. maybe its a more energetic conformation, the H-bonds between the bases forces it to adopt that structure. RNA is "always" single stranded so it doesnt have the pairing bases. Thats what I could come up with at the moment 🙂
actually, DNA can be single stranded. there are some viruses that have single stranded DNA as genetic material: phiX174, phiM16 etc..
DNA can even exist as a strange triple-stranded molecule, the triplex, or even as a tetraplex(if i remember correctly, this can happen if the DNA only consists of guanine bases)
it is just that evolution has favoured the duble stranded B-form DNA over the others because of the increased stability confered by hydrogen bonding and the possibility of long length.