Question

Which DNA double helix do you think would be harder to separate into two strands: DNA composed predominantly of AT base pairs, or of GC base pairs? Why?​

Answer 1

The DNA composed of GC base pairs would be harder to separate. This is because there are 3 hydrogen bonds and more stacking interactions between G and C. A and T only have 2 hydrogen bonds, making them less stable that GC base pairs

Answer 2

The DNA composed of CG base pairs will be difficult to separate because cytosine and guanine consist of triple bonds between them. Hence bond dissociation enthalpy will be greater as compared to AT base pairs.