Answer the following questions

1: Beta ( ) sheets are a type of secondary structure in proteins. A segment of a single chain in an antiparallel sheet has a length of 186 . How many residues are in this segment? number of residues

2:

A scientist is conducting a Sanger's sequencing experiment to determine the number of polypeptides present in an oligomeric protein. The molecular weight of the protein is 20000 g/mol20000 g/mol. After the reaction of 640 mg640 mg of the protein with 1fluoro2,4dinitrobenzene, the peptide bonds were hydrolyzed with an acid. As a result, the scientist obtained 21 mg21 mg of 2,4dinitrophenyl histidine.

What is the number of the polypeptide chains present in the oligomer?

1

2

31

4