What are OKAZAKI FRAGMENTS?
Okazaki Fragments are short lengths of DNA produced by discontinuous replication of the lagging strand , named after Reiji Okazaki, who discovered them. In bacterial cells, each Okazaki fragment ranges from about 1000 to 2000 nucleotides in length; in eukaryotic oraganism, they are about 100 to 200 nucleotides long.
Okazaki fragments on the lagging strand are linked together to create a continuous DNA molecule.
DNA is synthesised from 5' to 3', so when copying the 3' to 5' strand, replication is continuous. Phosphodiester links form between the 3' to 5' and nucleotides can be added with the aid of the enzyme DNA polymerase for the continuous leading strand. However, in order to synthesise the lagging strand (the 5' to 3' strand) synthesis must occur in small sections (100-200 nucleotides at a time in eukaryotes). These new stretches of DNA are" called Okazaki fragments and each one requires its own RNA primer.
