What characterizes the differences in stability between RNA and DNA?

The differences in stability between RNA and DNA are primarily characterized by the presence of a hydroxyl group in RNA. RNA contains a ribose sugar, which has a hydroxyl (-OH) group attached to the 2' carbon. In contrast, DNA has a deoxyribose sugar, which is missing this hydroxyl group – it only has a hydrogen atom at the same position.

The presence of the hydroxyl group in RNA makes it more reactive and less stable than DNA. This additional functional group allows for hydrolysis reactions to occur more readily, which can result in the degradation of RNA under alkaline conditions. In biological contexts, this instability is functionally significant, as it allows RNA to be more dynamically regulated and useful for temporary functions, such as protein synthesis. On the other hand, the more stable structure of DNA, which is designed for long-term storage of genetic information, helps to protect the genetic code across generations.

Considering this, the presence of the hydroxyl group is the critical factor that differentiates the stability of RNA from DNA.