Dna Replication Fork — a labelled NEET Biology diagram with a definitions lexicon.
DNA Replication Fork Labelled parts: Leading strand (continuous), Lagging strand (discontinuous), Template strand, Helicase, SSB proteins, DNA polymerase III, Okazaki fragments, RNA primers, Primase, DNA ligase, 5', 3'. The strand of DNA synthesized continuously in the 5' to 3' direction, moving towards the replication fork. This synthesis requires only one RNA primer at the origin. FYI: Because synthesis is continuous, the leading strand is synthesized much faster than the lagging strand. The strand of DNA synthesized discontinuously in short segments called Okazaki fragments, moving away from the replication fork. Each fragment requires its own RNA primer. FYI: DNA polymerase I is responsible for removing the RNA primers and filling the gaps on the lagging strand. Single-Strand Binding proteins that bind to single-stranded DNA templates at the replication fork. They prevent the separated strands from re-annealing prematurely. FYI: By keeping the strands separated, SSB proteins maintain the template structure necessary for DNA polymerase activity. The primary enzyme responsible for the rapid synthesis of new DNA strands during replication in prokaryotes. It possesses high processivity and proofreading capabilities. FYI: DNA Pol III has a 3' to 5' exonuclease activity, allowing it to proofread and correct mismatched bases immediately. Short segments of RNA synthesized by primase that provide the necessary free 3'-OH group to initiate DNA synthesis. DNA polymerase cannot start a chain de novo. FYI: The RNA primers are eventually removed and replaced with DNA nucleotides by DNA polymerase I. An enzyme that catalyzes the formation of a phosphodiester bond between two adjacent DNA fragments. It is essential for joining Okazaki fragments on the lagging strand during replication. FYI: DNA ligase requires ATP or NAD+ as an energy source to seal nicks in the DNA backbone.