137k views
5 votes
Why does a new DNA strand elongate only in the 5 to 3?

User Moberemk
by
7.7k points

1 Answer

4 votes
A new DNA strand elongates only in the 5 to 3 because the polymerase utilizes a deoxyribonucleotide, which then cleaves the two terminal phosphates from the 5' end of the nucleotide. Then it uses the free energy to form a phosphodiester bond. Therefore, in the end, the newly synthesized DNA strand can only elongate in one direction (5' to 3').
User Jkgeyti
by
8.1k points