Part III: Nucleic Acids
The Molecules of Heredity
DNA and RNA are the information-carrying molecules of life. The elegant double-helical structure of DNA, elucidated by Watson and Crick in 1953, enables faithful replication and transmission of genetic information. The central dogma — DNA → RNA → Protein — describes the flow of genetic information through transcription and translation. This part covers the structural biochemistry of nucleic acids and the molecular machinery of gene expression.
3.2 × 10⁹
Human Genome (bp)
3.4 Å
Base Pair Spacing
10⁻⁹
Polymerase Error Rate
Topics in This Part
9. DNA & RNA Structure
Nucleotide chemistry, Watson–Crick base pairing, double helix geometry, A/B/Z-form DNA, and RNA secondary structures
10. DNA Replication & Repair
Semiconservative replication, DNA polymerase mechanisms, proofreading, mismatch repair, and recombinational repair
11. Transcription & Translation
RNA polymerase, promoters, mRNA processing, the genetic code, ribosome structure, and translation mechanisms