HomeHelpContact usBack

Modules Open College - e-Learning Content Library
DNA replication process
Replication of deoxyribonucleic acid (DNA) is a process of duplication of DNA that is necessary, in particular, for cell division when genetic information coded in DNA, must be duplicated and divided between daughter cells. Helicase, topoisomerase and DNA-binding proteins untwine DNA, hold matrix in separated state and rotate the molecule of DNA. Accuracy of replication is provided by strong correspondence of the appropriate complementary nucleotides of DNA duplex and by activity of DNA-polymerase that is able to recognize and to correct any error. Several DNA-polymerases catalyze the replication. After replication the daughter strands rewind, this is realized without enzymes and with no energy consumption. The rate of replication is about 45000 nucleotides in minute, while the replication fork must rotate 4500 revos. Rate of errors occurrence during replication does not exceed 1 on 109-1010 nucleotides. If replication of DNA of eukaryotes proceeds with such rate then it should take several months to finish. To overcome the problem the replication in chromosomes of eukaryotes runs in hundreds or thousands of points at the same time. An animation of the model is operated by the "Start"/"Stop" and the "Reset" buttons.
© OpenTeach Software, 2007