What's the ratio? An acid with a pKapKa of 8.0 is present in a solution with a pHPH of 6.0. What is the ratio of the protonated to the deprotonated form of the acid? e

N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) buffer at pH 7 with 400 mM NaCl. A A purified protein is in a Hepes dialysis membrane tube holds a 5.0 mL sample of the protein solution. The sample tube floats in a beaker containing 0.50 L of the same Hepes buffer, but with 0 mM NaCl, for dialysis. Small molecules and ions (such as Na*, CI", and Hepes) can to diffuse across the dialysis membrane, but the protein cannot. Assume there are no sample volume changes during the dialysis. Calculate the final concentration of NaCl in the protein sample once the dialysis has come to equilibrium. Calculate the final NaCl concentration in the 5.0 mL protein sample after dialysis in 300 mL of the same Hepes buffer, with 0 mM NaCl, twice in succession. [NaCl] after a single dialysis: [NaCl] after a double dialysis: mM mM

A protein has a dissociation equilibrium constant equal to 4.0um. What is the concentration of free ligand when the fraction of bound sites is 0.7

An enzyme uses a lysine and a histidine as general acid-base catalytic residues. In one direction of the reaction, the lysine and histidine residues are typically protonated (~NH3*, ~Im), but in the other direction of the reaction, the two residues are "reverse protonated" (~NH2, ~Hlm*) (see below scheme). A pH profile of the reaction at various pH values yielded estimates of 7.57 and 9.30 for the macroscopic ionization constants pk,' and pK2, respectively. A separate set of experiments with site-speciffic variants of the enzyme yielded an estimate of 8.78 for the microscopic ionization constant pKp. Given this information, what is the value of the microscopic ionization constant pKA? Report your answer to the nearest hundredth. Lys-NH3* His-HIm" KB H KA H* Lys-NH2 Lys-NH3* His-HIm" His-Im Kc H* Kp Lys-NH2 His-Im