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DNA Replication
Mizzou, Spring 2015, Biochem Final
| Term | Definition |
|---|---|
| semi-conservative replication | each daughter double helix contains one template strand & one newly synthesized strand |
| origin of replication | DNA double helix unwinds at a specific point called an _____ ____ _____ |
| two replication forks | at each origin of replication, there are ____ ____ ____ |
| 5' to 3' | DNA is synthesized from its _________ end |
| DNA gyrase | relieves positive supercoils and relieves torsional stress; a type 2 topoisomerase |
| helicase | unwinds DNA helix and causes strand separation |
| SSB | (single-stranded binding protein) stabilizes single stranded regions & prevents re-annealing of DNA; protects single stranded regions from nucleases |
| primase | synthesizes the RNA primer |
| DNA ligase | seals nicks in DNA |
| DNA polymerase 1 | removes the RNA primer |
| DNA polymerase 2 | responsible for new strand synthesis |
| RNA | serves as a primer in DNA replication |
| primase | uses the DNA template strand to produce this RNA primer sequence |
| DNA polymerase 3 | synthesizes new DNA strands; the newly formed DNA is linked to the 3'-OH of the RNA primer |
| Okazaki fragments | are formed on the lagging strand due to the requirement for DNA synthesis in the 5' to 3' direction |
| DNA polymerase 1 | as the replication fork moves away, the RNA primer is removed by ____ _____ ___ as it fills the gaps |
| DNA ligase | makes the final covalent bond between Okazaki fragments |
| exonuclease | one proofreading function is the 3' to 5' ______ activity of DNA pol 1 |
| exonuclease | 5' to 3' _______ activity of DNA pol 1 is used to repair mutations in the DNA |
| mutation | DNA pol 1 removes ______ while inserting the correct DNA sequence |
| mismatch repair | enzymes recognize that two bases are incorrectly paired, the are of mismatch is removed, and the area replicated again |
| hundreds | each chromosome has _____ of replication origins |
| prokaryotes | DNA replication of _______: have 3 main polymerases, no histones complexed with DNA; Okazaki fragments of 1000-2000 residues long; all polymerases are exonuclease; ONE origin of replication |