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22 Cards in this Set
- Front
- Back
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Which is the only histone that is not in the nucleosome core? role?
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H1
ties nucleosomes together in a string |
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What is the charge of the histones?
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positive
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what is the charge of DNA?
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negative
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heterochromatin vs euchromatin
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HeteroChromatin= Highly Condensed, trancriptionally inactive
euchromatin= less condensed, transcriptionaly active |
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what is the nucleosome?
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core/bead of 4 histones
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Which bases are purines? how many rings do they have?
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AG (Pur As Gold)
2 rings |
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Which bases are pyrimidines? how many rings do they have?
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CUT (CUT they Py)
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Which base has a ketone?
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guanine
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which base has a methyl?
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thyamine
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How is cytosine made?
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deamination of uracil
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Which base pair bonds are strongest?
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GC (3-H bonds) are stronger than A-T (2-H bonds)
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What chemical properties of change when G-C content changes?
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inc. G-C content increases melting temperature
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Difference between nucleosides and nucleotides?
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sides= base + ribose (sides only)
tides= base + ribose + phospate (linked by 3-5 phosphodiester bond) |
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How are purines made?
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from IMP precursor
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how are pyrimidines made?
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from orate precursor, w/ PRPP added later
This leads to ribonucleoties that are converted to deoxyribonucleotides by ribonucleotide reductase |
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transition vs. transversion
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TransItion- Identical type= purine for purine or pyrimidine for pyrimidine substitution
Transversion- subs. purine for pyrimidine or vice versa |
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which amino acid is encoded by only 1 codon?
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methionine (AUG)
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rank these in most to leat severe mutations in DNA
silent, misence, nonsense |
nonsense > missense > silent
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silent mutation in DNA?
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same amino acid (often 3rd position-tRNA wobble)
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missense mutation in DNA?
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changes amino acid
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nonsense mutation?
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early stop codon
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frameshift mutation?
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change resulting in misreading of all downstream nucleotides
usually truncated, nonfunctional protein |
