What is the difference between DNA and RNA?

DNA and RNA are both examples of nucleic acids, and so are formed from long chains of nucleotides. However, there are three broad structural differences between the two. 1) DNA is usually found double-stranded, with two polynucleotide chains being bound together. By contrast, RNA is typically found single-stranded. The precise shape of an RNA molecule will depend on its function, for instance tRNAs which are shaped like clover leafs. 2) DNA contains the sugar deoxyribose, whilst RNA contains the sugar ribose. 3) DNA contains the bases adenine, thymine, guanine and cytosine, whereas in RNA thymine is replaced by uracil. These differences allow each molecule to be more effective at carrying out its purpose. DNA is used as a long-term store of genetic information, whereas RNAs are used to transfer the information from the DNA out of the nucleus in order to make proteins.