Origin of replication: Difference between revisions
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The double helical nature of DNA makes it very stable, and for replication to take place the | The double helical nature of [[DNA|DNA]] makes it very stable, and for replication to take place the [[hydrogen bonds|hydrogen bonds]] between complementary base pairs must be broken to expose the base pairs to allow [[nucleotides|nucleotides]] to bind. | ||
This unwinding and 'unzipping' (breaking of hydrogen bonds) always begins in specific sites within chromosomes.These sites are known as the 'Origin of Replication', as it is where DNA replication starts. This is often abbreviated to 'Ori c'.<ref> | This unwinding and 'unzipping' (breaking of hydrogen bonds) always begins in specific sites within [[chromosomes|chromosomes]].These sites are known as the 'Origin of Replication', as it is where DNA replication starts. This is often abbreviated to '[[Ori c|Ori c]]'.<ref name="Molecular Biology of the Cell, Alberts et al.,Fifth edition., 2012., 281-283.">Oric abbreviation</ref> | ||
In bacterial chromosome there tends to be only one origin of replication, and it tends to be opposite the terminal point of replication. | In bacterial chromosome there tends to be only one origin of replication, and it tends to be opposite the terminal point of replication.<ref name="Molecular Biology of the Cell, Alberts et al.,Fifth edition., 2012., 281-283.">bacteria have one OriC</ref> | ||
Linear DNA such as the human chromosomes tend to have more than one Ori C site as they replicate differently to circular bacterial DNA (which replicates bi-directionally), and tend to be larger and so would take longer to replicate if they only had one Ori C. | Linear DNA such as the human chromosomes tend to have more than one Ori C site as they replicate differently to circular bacterial DNA (which replicates bi-directionally), and tend to be larger and so would take longer to replicate if they only had one Ori C.<ref name="Molecular Biology of the Cell, Alberts et al.,Fifth edition., 2012., 281-283.">linear DNA has multiple Orics</ref><ref>Molecular Biology of the Cell, Alberts et al.,Fifth edition., 2012., 281-283.</ref> | ||
<references /> | === References === | ||
<references /><br> | |||
Latest revision as of 23:42, 26 November 2014
The double helical nature of DNA makes it very stable, and for replication to take place the hydrogen bonds between complementary base pairs must be broken to expose the base pairs to allow nucleotides to bind.
This unwinding and 'unzipping' (breaking of hydrogen bonds) always begins in specific sites within chromosomes.These sites are known as the 'Origin of Replication', as it is where DNA replication starts. This is often abbreviated to 'Ori c'.[1]
In bacterial chromosome there tends to be only one origin of replication, and it tends to be opposite the terminal point of replication.[1]
Linear DNA such as the human chromosomes tend to have more than one Ori C site as they replicate differently to circular bacterial DNA (which replicates bi-directionally), and tend to be larger and so would take longer to replicate if they only had one Ori C.[1][2]