This question's been bugging me for quite a while: why do they call it deoxyribosenucleic ACID, when it's actually basic, with all of those
base pairs?Nerro - 6-2-2005 at 03:51
The phosphate groups on the outside (the two stalks on of the ladder so to speak) are acidic.
dna
leo - 6-2-2005 at 06:37
becasue DNA is one 1/2 O2 lack from RNA. so they call it deox...acid.Pyrovus - 8-2-2005 at 01:49
Quote:
Originally posted by Nerro
The phosphate groups on the outside (the two stalks on of the ladder so to speak) are acidic.
Yes, but overall the whole thing would have to be basic. If the phosphate groups were mostly in the acidic form, then you'd end up getting a
zwitterion, with the bases accepting protons from the phosphate groups. As a result the bases would become positively charged, and the two strands
would then repel one another.Nicodem - 8-2-2005 at 11:45
Those amino groups on adenine, cytosine and guanine are very weak bases. These amino functions are even considerably less basic than the amino group
of aniline (pKa<4). They must also contribute to the hydrogen bonding and can only do so if not protonated. The hetereocyclic nitrogens in the
purine/pyrimidine rings are mostly not basic at all. On the other hand the phosphoryloxy gropus are quite acidic (pKa~3).
So all in all the whole DNA is an acid, though quite a weak one.
