DNA consists of the nucleotide bases:
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Thymine (T)
Base Paring Rules: G↔C, A↔T
A and G are purines (double‐ring), C and T are pyrimidines (single‐ring). The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three hydrogen bonds.
RNA consists of the nucleotide bases:
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Uracil (U)
Base Paring Rules: G↔C, A↔U
A and G are purines (double‐ring), C and U are pyrimidines (single‐ring).