The structural differences between DNA and RNA are based on their sugar component, nitrogenous bases, and strand structure. DNA contains the sugar 2-deoxyribose, whereas RNA contains ribose. Regarding the bases, DNA contains thymine, while RNA contains uracil; both contain adenine, guanine, and cytosine. Structurally, DNA exists as a double strand helix, while RNA is a single strand molecule that often folds back on itself.

Functionally, DNA acts as the chemical basis of heredity and contains the coded message for proteins to be synthesised in the cell. In contrast, RNA is responsible for carrying out protein synthesis. There are three types of RNA—messenger RNA (m-RNA), ribosomal RNA (r-RNA), and transfer RNA (t-RNA)—which perform different functions in the protein synthesis process.