DNA Replication

DNA replication is the process of producing identical DNA molecules and transferring genetic information to the next generation (CSU, n.d.; Spark Notes, 2014). Double helix unwinds, each strand separates to form a template for new DNA strand in the replication process (CSU, n.d.). Replication can be semiconservative and conservative. Each new strand acquires one strand from parent DNA in semi-conservative replication while an old set of strands and completes new set of strands and a complete new set of strands is formed in conservative replication (CSU, n.d.).

DNA replication involves a complex enzymatic activity. DNA polymerase, primase, ligase, helicase, single strand binding proteins, gyrase, telomerase are replication enzymes (Eric G Lambert School, 2014; Spark Notes, 2014; University of Leicester, 2010). DNA replication involves four steps: initiation, elongation, termination and proofreading and correction. At the very first stage of replication, hydrogen bonds between the nitrogenous bases break down (Eric G Lambert School, 2014). The double helix unwinds and two strands move in opposite directions in the initiation stage (Spark Notes, 2014). DNA polymerase is the enzyme placed between the two strands and produces nucleotides facilitating elongation of the strand (Eric G Lambert School, 2014). Some fragments, known as Okazaki fragments, contains newly formed DNA. The newly produced DNA molecule forms double helix structure after the completion of new strand at the termination stage (Eric G Lambert School, 2014). Proofreading and correction stage involves assessment of hydrogen bonding mismatch and accuracy of replication.

Replication process is different in prokaryotic and eukaryotic cells. More protein components are involved in eukaryotic replication however replication form moves ten times faster in prokaryotes than eukaryotes (University of Leicester, 2010). DNA replication is bi-directional. Only single origin of replication can be found in bacteria however eukaryotes have multiple origins of replication (University of Leicester, 2010).

References

California State University (CSU) (n.d.) DNA Replication [Online] Available at http://www.csun.edu [Accessed on 17 February 2014].

Eric G Lambert School (2014) Explain the Steps Involved in DNA Replication [Online] Available at http://www.ericlambert.ca/docs [Accessed on 21 February 2014].

Spark Notes (2014) DNA Replication and Repair [Online] Available at http://www.sparknotes.com [Accessed on 28 February 2014].

University of Leicester (2010) DNA Replication and Repair [Online] Available at www2.le.ac.uk [Accessed on 17 February 2014].

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