One method for separating polypeptides utilizes their different solubilities. The solubility of large polypeptides in water depends upon the relative polarity of their R groups, particularly the number of ionized groups. The more ionized groups there are, the more soluble the polypeptide. Which of each pair of the polypeptides that follow is more soluble at the indicated pH? a. (Phe-Met)3 or (Glu)m at pH 7.0

b. (Lys-Ala)3 or(Gly)m at pH 7.0

c. (Ala-Ser-Gly)5 or (Asn-Ser-His)5 at pH 6.0

d. (Ala-Asp-Gly)5 or (Asn-Ser-His)5 at pH 3.0:

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

What is the mass of phosphorous in a 51-kg person