Identify two differences in chemical composition that distinguish DNA from RNA.

Key Concepts

Nucleotide Structure

DNA and RNA are both nucleic acids composed of nucleotides, but their structures differ. DNA nucleotides contain deoxyribose sugar, while RNA nucleotides contain ribose sugar. This difference in sugar affects the stability and function of the molecules, with DNA being more stable and suited for long-term genetic storage.

Nitrogenous Bases

Both DNA and RNA are made up of nitrogenous bases, but they differ in one of these bases. DNA contains adenine (A), thymine (T), cytosine (C), and guanine (G), whereas RNA contains adenine (A), uracil (U), cytosine (C), and guanine (G). The presence of uracil in RNA instead of thymine is crucial for RNA's role in protein synthesis.

Strand Structure

DNA typically exists as a double-stranded helix, providing a stable structure for genetic information, while RNA is usually single-stranded. This difference in strand structure influences their functions; DNA serves as a long-term repository of genetic information, whereas RNA plays various roles in translating that information into proteins.