DNA Replication

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Since DNA is the genetic code for the synthesis and development of whole organisms, it must be copied exactly from one generation to the next. This is achieved by self-replication, using a semi-conservative mechanism in which each strand acts as a template for the synthesis of a new strand. Each new DNA molecule contains one of the original strands in addition to a new strand (hence the name semi-conservative). DNA replication takes place before the chromosomes duplicate during the process of mitosis and meiosis.

  • The enzyme DNA helicase breaks the hydrogen bonds holding the base pairs together and 'unzips' part of the DNA double helix, revealing two strands.
  • The enzyme DNA polymerase moves along each strand, which acts as a template for the synthesis of a new strand.
  • DNA polymerase catalyses the joining of free deoxyribonucleotides to each of the exposed original strands, according to base pairing rules, so that new complementary strands form
  • The process of unzipping and


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