Term
| Name three kinds of rearrangement |
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Definition
| Translocations, inversions, & duplications |
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Term
| Rearrangement mutations can involve up to how many base pairs? |
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Definition
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Term
| Define a chimeric gene product |
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Definition
| A type of rearrangement that fuse two genes together in such a way that alters gene expression of one or both fused genes. |
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Term
| Insertion and deletion mutations usually involve how many base pairs? |
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Definition
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Term
| The overall mutation frequency in humans is… |
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Definition
| 1 event per 10^9 - 10^10 bases synthesized |
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Term
| What accounts for the low mutation rate? |
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Definition
| DNA pol has error rate 10^-5 per base + 3' -5' exonuclease adds 10^-2 per base + DNA repair mechanisms 10^-2 = 10^-9 per base error rate. |
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Term
| A mutation in which an adenine is substituted for a guanidine is… |
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Definition
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Term
| What event is more likely: a cytosine is substituted for thyamine or a cytosine is substituted for adenine? |
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Definition
| Cytosine for thymine (transition) is more likely that cytosine for adenine (transversion). |
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Term
| When a single substitution mutation at the DNA/RNA level has no effect on the protein encoded, it is known as… |
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Definition
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Term
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Definition
| Mutations that cause a different amino acid to be inserted to the protein; essentially a point mutation. Remember "don't miss the point" |
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Term
| Why are nonsense mutations exceptionally dangerous? |
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Definition
| A nonsense mutation causes a change from any amino acid to one of the three stop codons, prematurely terminating protein translation. Remember "stop the nonsense" |
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Term
| A frameshift mutation can only occur when… |
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Definition
| Insertion or deletion of nucleotides is not a multiple of three. |
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Term
| A single strand of RNA has how many possible reading frames? |
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Definition
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Term
| How does base stability contribute to mismatch mutations in DNA? |
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Definition
| Base tautomerization of functional groups amino <--> imino, keto <--> enol leads to transition mutations (A:C and G:T). |
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Term
| Deamination of adenosine produces inosine which pairs with cytosine. This mutation is best characterized as… |
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Definition
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Term
| The term "slippery" in DNA replication refers to… |
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Definition
| Repeat sequences that can align in the wrong register resulting in insertions or deletions. |
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Term
| Deamination of 5-methyl-cytosine produces |
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Definition
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Term
| Deamination of cytosine makes a |
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Definition
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Term
| The frequency of CG dinucleotides at CG islands is more, less or equal to the expected frequency? |
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Definition
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Term
| In non-CG island regions of the genome, the frequency of CG dinucleotide is less than expected. Why? |
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Definition
| DNA methylation at 5'-CG followed by deamination of 5-methyl-cytosine produces thymine. |
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Term
| Alkylating agents modify DNA by one of two methods: |
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Definition
| Either transferring a methyl or other alkane moity to base or by crosslinking two paired DNA strands together. |
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Term
| The method by which intercalators disrupt DNA |
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Definition
| Intercalators are planar aromatic compounds that bind between DNA bases and cause distortion to duplex. |
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Term
| What mutation do intercalators often cause? |
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Definition
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Term
| Psoralens are found in what vegetable and used to treat…. |
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Definition
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Term
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Definition
| Fungi. Humans often exposed via contaminated peanuts. |
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Term
| UV radiation can cause what type of DNA damage? |
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Definition
| Adjacent, stacked pyrimidine bases can form covalent linkages called cyclobutane dimers. |
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Term
| Cyclobutane dimers between what base type(s) is considered the most dangerous? |
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Definition
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Term
| Ionizing radiation such as high energy x-rays or gamma rays damage DNA similar to what chemical process? |
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Definition
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Term
| Spontaneous hydrolysis of the N-glycosidic bond leaves abasic nucleotides of DNA. How do the hydrolysis rates between purines and pyrimidines compare? |
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Definition
| Purines hydrolyse off 20x faster than pyrimidines |
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Term
| How is the mutagenicity of a something ascertained? |
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Definition
| The Ames test using the HERP scale. |
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Term
| What two factors are considered in the HERP scale? |
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Definition
| The toxicity and relative likelihood of exposure by average person. |
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Term
| How is it that natural products can pose a greater danger than man-made chemicals? |
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Definition
| Our exposure to natural products is much higher and their toxicity is often as high as sythetic chemicals. |
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