1. Sugar: DNA contains deoxyribose sugar, while RNA contains ribose sugar. The difference lies in the presence of a hydroxyl group (-OH) on the 2' carbon of ribose, which is absent in deoxyribose. This subtle difference impacts the stability and reactivity of the molecule.
2. Nitrogenous Bases: Both DNA and RNA contain adenine (A), guanine (G), and cytosine (C). However, DNA contains thymine (T), while RNA contains uracil (U) instead. Uracil lacks a methyl group present in thymine.
3. Structure: DNA is a double-stranded helix, with two anti-parallel strands held together by hydrogen bonds between complementary base pairs (A-T and G-C). RNA is typically single-stranded, although it can fold into complex three-dimensional structures due to intramolecular base pairing.
These differences in structure lead to their distinct roles in the cell: DNA serves as the genetic blueprint, while RNA plays various roles in gene expression, such as carrying genetic information from DNA to ribosomes for protein synthesis.
