DEV2011 Lecture Notes - Lecture 3: Okazaki Fragments, Helicase, Dna Replication
14 Apr 2020
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Document Summary
Dna replication is the biological process by which two identical copies of the dna from one original dna molecule can be made. This process occurs in all organism acting as the basis for biological inheritance. Dna is double stranded antiparallel which can only be replicated in 5" prime to 3" prime direction. Step 1: the enzyme dna helicase unwinds and unzips the parent dna molecule. Step 2: rna primase which is an enzyme adds a short segment of rna, called an rna primer on each dna strand. This gives the dna bases something to attach to when they are laid down. Step 3: dna polymerase another enzyme adds appropriate nucleotides to the new dna strand in the 5" to 3" direction. The strands of dna are being copied in opposite directions. Leading strand: gets replicated in one continuous piece: lagging strand: is replicated discontinuously in small pieces called okazaki fragments.
