Question

DNA in water. Would you expect the double helix in a short segment of DNA to be more stable in 100 sodium phosphate buffer at pH 7.0 or in pure water? Why?

Answer 1

Explanation:

DNA is composed of large amount of amino acids and have a lot of amide groups .

Therefore , in the acidic or in basic medium , the DNA molecules is either dissociated  or dis stabilized via protonation or de protonation .

The double helix structure of the DNA may break or get dis ordered .

But , from the question , In sodium phosphate buffer at pH = 7.0 , is the neutral condition , hence , the DNA remains unchanged , because of the neutral medium .

And in pure water ,

The DNA molecule remains intact as , in pure water , there are no ions .