Why is one strand of DNA copied continuously than the other strand of DNA?
The reason is two-fold: 1)DNA polymerase always copies from 5′ to 3′ 2)You have a LOT of DNA. One could imagine that when it comes time to replicate your DNA, your two strands completely dissociate and the polymerase comes in and happily transcribes both strands continuously from 5′ to 3′. However, this is not the case. You have so much DNA that dissociating completely is untenable (not to mention dangerous for your DNA). So instead, using helicases, the DNA is unwound just before the polymerase as it travels from 5′ to 3′. So, one strand is copied continuously. The other strand has a problem, though. While the first strand is being unwound from 5′ to 3′, it is being unwound 3′ to 5′. The polymerase can’t bind! As a solution, Okasaki fragments are formed by primases, which the polymerase binds to and then travels 5′ –> 3′ along the second strand, creating only a short length of DNA before it hits previously-made DNA. by the time this happens, however, the helicase has moved on, unrave
