Nucleotides Would both daughter strands be radioactive Expla

Nucleotides? Would both daughter strands be radioactive? Explain. How would the process of DNA replication be different if DNA III could synthesize DNA in both the 5\' -> 3\' AND 3\' -> 5\' directions? Briefly explain your answer. (

Solution

To add nucleotides to the DNA strand being synthesized, the 3\'-OH bond is cleaved. One oxygen molecule is removed from the phosphate group. The oxygen molecule removed is also attached to Mg++. MG++ pulls the electrons of oxygen, thus weakening the bond. This is the nucleophilic attack of the oxygen from the 3\'OH and this forms a phosphodiester bond.

To synthesize in the reverse 3\'->5\' direction you would need nucleotide-3\'-triphosphate instead of the nucleotide-5\'-triphosphate. This would allow a similar mechanism of replication but with different nucleotides as substrates. Also the nucleophilic attack would require more energy.