Question

Discuss how linear DNA molecules are replicated.

Answer 1

There are two strands in the DNA molecules : leading strand and lagging strand.

The replication occurs in following steps:

* DNA helicase binds to the site of ori. Ori stands for origin of replication. This leads to unwind the DNA.

* Then topoisomerase cuts and rejoin the DNA strand so that tension is relieved.

* RNA primase synthesises the RNA primer.

* RNA primase privides 3' OH end for the action of DNA polymerase 3.

* DNA polymerase synthesises the new strand of DNA with respect to the compelmentary sequence of parental strand of DNA.

* Now there are differences in keading and lagging strand DNA synthesis. There is found continuous syntheisis of DNA on Leading starnd. But on kagging strand, discontinuous synthesis of DNA fragemnts occurs. These fragments are known as okazaki sements.

* After that ligase joined these okazaki fragments.

* Then DNA polymerase 1 acts in the RNA primer and removes them by exonuclease activity. The deoxyribonucleotide are added in this place by DNA polymerase.

Please loon in the image for DNa replication:

* Leading Helicase origin of replication kellagging b y 5', T ökazani na kunwinding U t a3 adaki i ökazaki. A fragments & Okazaki those 13? fragment 3'T HAS Zagabing Leacting to tortor 1 - Originals ONA fe - New ONA la primera li į kaitis !