Suggest why DNA is a more suitable long-term storage molecule for genetic information than RNA.

DNA and RNA have similar, but not identical, molecular structures. It is these structural differences that enable DNA to be a more suitable long-term storage molecule than RNA. Firstly, the pentose sugar in a DNA monomer is β-D-2-deoxyribofuranose, whereas in an RNA monomer, the pentose sugar is β-D-ribofuranose. The hydroxyl group on C2’ of β-D-ribofuranose causes RNA to be more polar and more susceptible to hydrolysis, especially in the aqueous cytoplasm of a cell. Secondly, thymine is found as a nitrogenous base in DNA. However, in RNA, thymine is replaced by uracil. This means that DNA has a lower mutation rate, as spontaneous deamination reactions of cytosine to uracil can be readily detected by the cell’s mismatch repair machinery. (This is less readily recognised in RNA, since uracil is present in RNA to begin with.) Thirdly, RNA tends to be single stranded. DNA, on the other hand, exists usually as a double helix. The pentose-phosphate backbone of the double helix protects the bases within from chemical damage, preserving the base sequence.Note that there are certain exceptions to these key differences in both RNA and DNA, which further affect how suitable each molecule is for long-term storage of genetic information.