7. How is phenyl Isothiocyanate useful in determining protein structure? 8. The absorption coefficient of bovine immunoglobulin at 280 nm is 210,000 M cm What is the absorbance of a 0.1 mg ml solution across a 1-cm path? What percentage of the incident light is transmitted by this solution? (Hint: check question 3.4 in the textbook) 9. The relative electrophoretic mobilities of a 30-kDa protein and a 92 kDa protein used as standards on an SDS-polyacrylamide gel are 0.80 and 0.41, respectively. What is the apparent mass of a protein having a mobility of 0.62 on this gel? 10. A peptide digested with trypsin produced the following three fragments: C, ASFPK, and GGRWDGdK The same peptide digested with chymotrypsin produced the following three fragments: PKGGRW, DGKC and ASF What is the primary structure of the peptide?