Okasaki fragments are short fragments of DNA formed on the lagging strand during bidirectional semiconservative DNA replication. DNA unwinds and the two strands split forming two forks. One of the strands goes from 5’ to 3’ and is called the leading strand, the other strand goes from a 3' to 5' and is called the lagging strand. The lagging strand is synthesized discontinuously in the form of short fragments this is because DNA synthesis can proceed only in the 5' to 3' direction. The strands are later fused together by DNA ligase to form the full, unfragmented DNA strand. Each new origin of replication (where the DNA polymerase joins) requires a separate RNA primer.
- ↑ http://www.biology-online.org/dictionary/Okazaki_fragment
- ↑ Sakabe K, Okazaki R (December 1966). "A unique property of the replicating region of chromosomal DNA". Biochimica et Biophysica Acta 129 (3): 651–54. doi:10.1016/0005-2787(66)90088-8. PMID 5337977.