posted by Anonymous .
a closed circular DNA molecule has 3675 base pairs and a topological linking number (Lk) of 345. Using 10.5 base pairs per turn, what would the writhe number (Wr)be for the molecule in order for it to optimize its base pairing??
I'm guessing we use the formula Lk= Tw+Wr.
However what is Tw?
Twists aka turns. You can calculate the number of turns if you know how many bp/turn this DNA molecule has, since you know the number of bases.
10.5 bp/turn is standard for B form DNA