The leading strand is made continuously, while the lagging strand is made in short Okazaki fragments.
Because polymerase works only 5' to 3', one strand is made continuously toward the fork (leading) and the other discontinuously away from it (lagging). The lagging strand needs repeated priming, which makes the process more complex.
The replication fork is asymmetric but the polymerases are coordinated in a replisome.
The leading strand is made continuously, while the lagging strand is made in short Okazaki fragments.
Leading and Lagging Strands is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Okazaki Fragments, DNA Polymerase, Primase and RNA Primer.
The lagging strand has many more primers than the leading strand.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Leading and Lagging Strands. Intermediate topics assume the Beginner vocabulary.
The closest topics to Leading and Lagging Strands are Okazaki Fragments, DNA Polymerase, Primase and RNA Primer, Transcription. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Leading and Lagging Strands. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Leading and Lagging Strands: The leading strand is made continuously, while the lagging strand is made in short Okazaki fragments. Okazaki Fragments: Short DNA segments synthesised discontinuously on the lagging strand and joined by DNA ligase. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Okazaki Fragments and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
Short DNA segments synthesised discontinuously on the lagging strand and joined by DNA ligase.
🧫 Molecular BiologyThe enzyme that adds nucleotides to a growing DNA strand in the 5 prime to 3 prime direction.
🧫 Molecular BiologyPrimase lays down a short RNA primer that gives DNA polymerase a starting 3 prime end.
🧫 Molecular BiologyThe process of making an RNA copy of a gene using DNA as a template.
🧫 Molecular Biology