Leading Strand

∞ generated and posted on 2016.08.28 ∞

During DNA replication, that half of the parental double helix that is replicated continuously as the replication fork opens.

See by contrast lagging strand, discontinuous synthesis, and Okazaki fragments.

The leading strand is replicated continuously because the newly synthesized DNA strand "points" towards the replication fork with its 3' end. That is, nucleotides are added to this end since DNA is (always) synthesized in the 5' → 3' direction. As a consequence, each time the replication fork unwinds the parental DNA double helix by one nucleotide then an additional one nucleotide can be added to the end of the leading strand, that is, as it is synthesized towards the opening replication fork.