DNA Stability Maintains the Integrity of Genetic Information
- During transcription, DNA serves as a stable template for synthesizing RNA.
- The DNA base sequence does not change during transcription, even though it is used repeatedly as a template.
- In somatic cells that do not divide (e.g., nerve cells, muscle cells), the DNA sequence must remain conserved throughout the entire life of the cell.
- Somatic cells are all the cells in your body except sperm and egg cells.
- These cells do not pass genetic information to offspring but must maintain their DNA to function properly.
How DNA Maintains Stability During Transcription
DNA maintains its stability through three key mechanisms.
1. Temporary Unwinding of the Double Helix
- During transcription, the DNA double helix unwinds only in the region where RNA polymerase is active.
- This unwinding is temporary and localized, minimizing the exposure of DNA to potential damage.
The DNA strands re-anneal (rejoin) immediately after RNA polymerase passes, restoring the stable double-helix structure.
2. Hydrogen Bonding and Complementary Base Pairing
- DNA’s stability relies on hydrogen bonds between complementary bases (A-T and C-G).
