DNA polymerase 3 is also called as holoenzyme and it is the most essential component of replisome. Difference in function. DNA polymerase 1 functions helps in DNA replication. It is used for molecular biology research.During the process of replication, an RNA primer is filled in the lagging strand of the DNA.NA polymerase 1 vs 3. DNA polymerases are specially designed enzymes which help in formation of DNA molecules by assembling tiny building blocks of DNA called as nucleotides. DNA polymerase helps in splitting of the DNA molecule into two identical DNAs.