Term
| How are replication errors repaired? |
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Definition
| DNA polymerase has a proofreading mechanism. Also, mismatch repair. |
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Term
| How does mismatch repair work? |
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Definition
| It recognizes kinks due to bad base pairing. It then replaces the bases. |
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Term
| What types of errors are caused by chemical mutagens (like reactive oxygen species? |
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Definition
| deamination of cytosine, oxidation of G |
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Term
| What does deamination of cytosine do? |
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Definition
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Term
| What does oxidation of G do? |
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Definition
| It makes it bond with A instead of C. |
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Term
| How can chemical modification of bases be repaired? |
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Definition
| Base excision, or direct repair of the base |
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Term
| How does base excision work? |
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Definition
| cut the base out and replace it. |
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Term
| What does UV damage do to DNA? |
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Definition
| causes Thymine dimers (pyrimidine dimers) |
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Term
| How can pyrimidine dimers be repaired? |
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Definition
| Nucleotide excision, or translesion synthesis |
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Term
| How does nucleotide excision work? |
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Definition
| Kink is identified by the dimer. The kink is chopped out and DNA poly epsilon fills in the bases. |
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Term
| What skin disease is associated with a problem with nucleotide excision? |
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Definition
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Term
| What does ionizing radiation do to DNA? |
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Definition
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Term
| How are double stranded breaks repaired? |
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Definition
| Non-homologous end joining (inaccurate though), recombination |
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Term
| How does non-homologous end joining work? |
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Definition
| The ends of the cut DNA are just ligated together |
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Term
| How does Recombination work? |
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Definition
| Need a 2nd DS DNA. the defective DNA can like invade the other one and copy it. Then there is recombination because part of each DNA ends up in the other one when the two dsDNAs separate. |
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