Difference between Leading strand and Lagging strand

The DNA replication process is generally referred to as discontinuous, because the polymerizing enzyme can add nucleotides only in the 5’-3’ direction, synthesis in one strand(leading strand is continuous in the 5’-3’ direction towards the fork. In the other strand (lagging strand), as the forks opens, multiple sites of initiation  are exposed. The synthesis, then proceed in short segments in the 5’-3’ direction: that is, synthesis in the lagging strand is discontinuous. The short segments of DNA synthesized on the lagging strand are called Okazaki fragment. These fragments are about 1000 – 2000 nucleotide long.
Leading strand and Lagging strand
No Leading strand Lagging strand
1 It is a replicated strand of DNA which grows continuously without any gap Lagging strand is replicated strand of DNA which is formed in short segments called okazaki fragments. Its growth is discontinuous
2 It does not require DNA ligase DNA ligase is required for joining Okazaki fragments
3 The Direction of growth of the leading strand is 5’-3’ The Direction of growth of the lagging strand is 3’-5’ through in each Okazaki fragment it is 5’-3’
4 Only a single RNA primer is required Starting of each Okazaki fragment requires a new RNA primer
5 Formation of leading strand is quite rapid Formation of lagging strand is slower
6 Its template open in 3’-5’ direction Its template open in 5’-3’ direction
7 Formation of leading strand begins immediately at the beginning of replication. Formation of lagging strand begins a bit later than that of leading strand
Previous Post Next Post