3) Suppose the major solutes in intact lysosomes are KCI (-0.1 M) and NaCl (-0.03 M). When isolating lysosomes, what concentration of sucrose is required in the extracting solution at room temperature (25°C) to prevent swelling and lysis? 4) The following questions will help you review and understand pH, pKa, and buffering by weak acids/bases. a) Water is a weak acid; write the ionization reaction of water and the expression that describes its K. (Hint: K, is the equilibrium constant for proton dissociation). b) What is the concentration of H* in a solution of water when the concentration of OH = 108 M? What is the pOH of this solution? What is the pH? Is the solution acidic or basic? c) Draw a titration curve for a molecule with a pKa = 4.7 and label all the axis, indicating clearly the buffering region and the pKa value. d) Calculate the fraction of histidine (amino acid shown below), that has its imidazole side chain protonated at pH 6.4. The pK, value for the imidazole group of histidine is 6. Protein CH₂ Protein NH NH pH5 pH 7 CH+H