Term
| The fact that both strands of DNA will be copied and kept after replication means that the process of DNA replication is _________ |
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Definition
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Term
| How many ORI's do prokaryotes typically have? |
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Definition
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Term
| Eukaryotes have _____ origins of replication |
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Definition
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Term
| What is the name of the factor that denatures DNA (prokaryotes)? |
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Definition
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Term
| What is the name of the enzyme that unwinds DNA (prokaryotes)? |
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Definition
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Term
| What is the name of the proteins that keep the two DNA strands separate (prokaryotes)? |
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Definition
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Term
| What is the function of Topoisomerase I? |
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Definition
| Causes a single nick in replicating DNA to relieve the tension of positive super coiling |
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Term
| What is the function of Topisomerase II (DNA Gyrase) in prokaryotes? |
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Definition
| Topisomerase II causes a double strand break so that prokaryotic DNA can be packed in a negative supercoil. |
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Term
| What is the function of Topisomerase II in humans? |
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Definition
| Changes the topography of DNA to allow gene expression and replication |
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Term
| Drugs that inhibit Human Topoisomerase II are typically trying to combat what disease? |
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Definition
Cancer
these drugs stop DNA replication and cause cell apoptosis |
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Term
| Drugs that inhibit the action of DNA gyrase are typically targeting what diseases? |
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Definition
Bacterial infections
Gyrase is the topoisomerase II found in prokaryotes |
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Term
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Definition
| The protein machinery of DNA replication |
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Term
| What is the function of Primase? |
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Definition
| Primase creates the RNA primer that polymerase recognizes to begin synthesis |
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Term
[image]
Identify the structures |
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Definition
1: RNA Primer
2: Newly synthesized DNA strand
3: Leading Strand
4: DNA polymerase III
5: ssDNA binding proteins
6: Helicase
7: Primase
8: Okazaki Fragment
9: Lagging Strand |
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Term
| What are Okazaki Fragments and how are they created? |
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Definition
| Okazaki fragments are fragments of newly synthesized DNA. They are caused by synthesis on the lagging strand because DNA can only be synthesized on the 5'->3' direction which calls for periodic breaks in synthesis. |
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Term
| What is the function of DNA ligase? |
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Definition
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Term
| How are the gaps in the Okazaki Fragments filled? |
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Definition
| DNA polymerase I excises RNA primer and synthesizes over the gaps. DNA ligase repairs the nicks. |
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Term
| What is the function of DNA polymerase III |
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Definition
synthesis in the 5'->3' direction
proofreading in the 3'->5' direction |
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Term
| What are the three steps that keep error rates low in bacterial and human genomes? |
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Definition
5'->3' polymerization
3'->5' exonucleolytic proofreading
Strand-directed mismatch repair |
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Term
| What is the function of Polymerase alpha? |
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Definition
| Primase analog, also initiates DNA synthesis |
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Term
| What is the function of Pol Beta? |
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Definition
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Term
| What is the function of Pol Gamma? |
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Definition
| Replicated Mitochondrial DNA, proof-reading |
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Term
| What is the function of Pol Delta? |
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Definition
| Polymerase I analog, elongates Okazaki Fragments. Also proofreads |
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Term
| What is the function of Pol Epsilon? |
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Definition
| Polymerase III analog, leading strand sythesis and DNA repair. Also Proofreads |
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Term
| How does acyclovir work mechanistically to reign back Herpes Simplex 1? |
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Definition
| Acyclovir is a nucleoside analog with no 3'OH (causes chain termination). Replaces guanisine and stops DNA polymerase from recognizing the primer |
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Term
| What happens to nucleosomes during replication? |
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Definition
| Nucleosomes only partially break during replication. After replication histone chaperones rebuild the partial nucleosomes mainting structural and epigenetic principles |
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Term
| What happends to the histone code during replication? |
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Definition
| Roughly half of the histone marks are preserved during replication but complex reader-writer proteins manage to recreate the code and preserve epigenetic gene expression |
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Term
| What is the function of telomeres? |
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Definition
| Telomeres protect the DNA from degradation by nucleases. Structurally this occurs by created a T-loop that leaves no ends that can be chewed |
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Term
| What is the function of telomerase reverse transcriptase? |
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Definition
Prevent the shortening of telomeres after replication.
mechanistically: enzyme with associated RNA code that creates a DNA telomere repeat sequence and adds it to the parental strand |
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