Formation of a 3' - 5'
phosphodiester
bond in DNA synthesis
During DNA
synthesis, new
nucleotides
are added to the existing 3' end of the strand, by a 3'
- 5'
phosphodiester bond (R - O - P - O
- R). The original 5' end remains
unmodified: polynucleotides thus "grow" by addition at the 3' end,
in the 5'
3' direction.
Nucleic
acid biochemical processes occur only in
the 5'3'
direction. Don't try to think of them any other
way.
Figure © 2000 by Griffiths et al. ; text © 2024 by Steven M. Carr