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17 Cards in this Set
- Front
- Back
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how to measure DNA quality
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electrophoresis
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electrophoresis
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confirms presence of purified DNA visually and gives a qualitative overview of DNA purity. when unknown DNA is compared side by side with markers of known molecular weights and quantity, the relative intensity of the unknown DNA to the marker DNA bands can be estimated.
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how is size determined in electrophoresis
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based on standard curve generated by the markers.
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gel medium used in this lab
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agarose, polysaccharide extracted from seaweed.
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nucleic acid absorbs light mostly at...
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260 nm
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how does it indicate good nucleic acid purity?
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when absorption ratio of 260nm/280nm is high (>1.8)
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at 260 nm, each absorbance unit is equal to
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50 ug/ml of DNA.
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to estimate the concentration of DNA, you need to...
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convert the concentration of sample used in spectrophotometry and multiply that value by 50 ug/ml to yield concentration of purified sample.
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what provides a quantitative measure of concentration of DNA?
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spectrophotometry.
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what rate are we determining?
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rate at which substitutions occur in RNA polymerase II B' subunit gene in order to set the "molecular clock"
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the branch point where two lineages diverged is also known as
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evolutionary distance or "age for most-recent common-ancestor" (MRCA), associated with age of divergence and is measured in million years.
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lineages become differentiated when...
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populations become reproductively isolated, genetic mixing does not occur, and accumulate unique mutations that are distinct.
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why are you able to estimate times of divergence between two lineages?
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because these mutations occur at relatively constant rate for a particular genes.
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rate of change is known as
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molecular clock,
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what is molecular clock used for?
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to time divergence events based on sequence differences.
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what is responsible for transcribing all mRNAs in eukaryotes?
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RNA polymerase II
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what are we using that encodes genes?
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RNA polymerase II B' subunit (RPB1), largest subunit of RNA polymerase.
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