A sample of PET polymer (C1OH8O4) contains 30% molecules with molecular mass 20,000 g/mol, 40% with molecular mass 30,000 g/mol and 30% with molecular mass 60,000 g/mol. Compute for the degree of polymerization. Use C = 12.01 g/mol, H = 1.01 g/mol, O = 16.00 g/mol. * %3D

if you perform a 1:5 dilution of a 1 M solution , how many parts of the 1 M solution do you use, and how many parts of the diluent do you use?

A purified protein fraction has a total sample volume of 360 µL.  The sample has a corrected A280 of 0.484, and the blank corrected A280 was 0.052.  (Both values were measured with a path length of 1.00 cm.)  If 5.00 µL of the sample was used in a reaction, calculate the mass of protein in the reaction (in µg).

The twisted proteins store elastic potential energy as it twists or untwists from its equilibrium state.  The energy function for this system is shown in the figure where the energy is given in multiples of kBT  which is a unit of energy used by biochemists when working at the molecular level.  (1.0 kBT = 4.11×10−21 J). Figure 6 shows a horizontal line at an energy level of 136 kBT , which gives a total angular range of 2.095 radians.  If the energy level of the ATP-synthase stalk is 100 kBT instead,  between what angles is the stalk confined?  Explain your reasoning.