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Physical Cell BiologyLecture 14:DNA and random walks

DNA: Phillips, Chapter 8,, Pollard chapter 7-9

Levels of AbstractionMicrotubuleDNA

Polyethylene

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Molecules as chains of small units

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Polymer configuration as a random walk

Distribution of End to End Distances

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Radii of Gyration for Different Chromosomes

Persistence Length

Figure from : Liverpool, T.B., “Active gels: where polymer physics meets cytoskeletal dynamics” Philosophical Transactions of the Royal Society – A, 364(1849), 2006, p. 3335-3355

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DNA and persistence length scales

Single Molecule Mechanics

AFM

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Force extension experiments

Optical trap/tweezers

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Magnetic tweezers

Pipette based force measurements

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