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hvfuente
When a polymer like DNA is dissolved at low concentration, each molecule assumes a random spherical coil conformation in the solvent. The radius of this random coil is given by the following equation:
R_g=√((L_0 l_p)/3)
where L0 is the contour length (total end-to-end length if the polymer were stretched out all the way) of the polymer and lp is its persistence length (a measure for its stiffness). What happens to the packing density of the DNA inside the coil, i.e., the ratio of DNA to water, when the contour length increases? Does it get more or less tightly packed, or stay the same? Explain your reasoning using the equation above. Assume that the salt concentration is sufficiently high to effectively screen all electrostatic interactions.
R_g=√((L_0 l_p)/3)
where L0 is the contour length (total end-to-end length if the polymer were stretched out all the way) of the polymer and lp is its persistence length (a measure for its stiffness). What happens to the packing density of the DNA inside the coil, i.e., the ratio of DNA to water, when the contour length increases? Does it get more or less tightly packed, or stay the same? Explain your reasoning using the equation above. Assume that the salt concentration is sufficiently high to effectively screen all electrostatic interactions.