1. Sugar Molecule:
- DNA: Contains deoxyribose sugar.
- RNA: Contains ribose sugar. The difference is the presence of an extra hydroxyl group (-OH) on the 2' carbon of ribose.
2. Nitrogenous Bases:
- DNA: Contains adenine (A), guanine (G), cytosine (C), and thymine (T).
- RNA: Contains adenine (A), guanine (G), cytosine (C), and uracil (U). Uracil replaces thymine in RNA.
3. Structure:
- DNA: Typically exists as a double helix, with two strands running in opposite directions (antiparallel) and held together by hydrogen bonds between the bases.
- RNA: Typically exists as a single-stranded molecule, although it can fold into complex three-dimensional structures.
Important Note: There are exceptions to the structural difference. Some RNA molecules, such as some viral RNAs, can form double-stranded structures.
