Organic Chemistry 354 Quiz - December 8, 2000

Dr. Sundin

1. A nonapeptide gave the following amino acids on complete hydrolysis:

Ala, Asp, Glu, Gly, Leu, Lys, Phe, Tyr, Val

Edman degradation gave Gly while carboxypeptidase A gave Val.

Chymotrypsin hydrolysis (to the right of Phe, Try, Tyr) of the nonapeptide gave several fragments of which only two were isolated in any quantity, a pentapeptide and a tetrapeptide. Hydrolysis of the tetrapeptide gave the three dipeptides below:

Ala, Val; Asp, Ala; Asp, Phe

Trypsin hydrolysis (to the right of Arg and Lys) of the nonapeptide gave only two fragments, a pentapeptide and a tetrapeptide. Complete hydrolysis of this tetrapeptide gave: Glu, Leu, Lys, Gly.

Partial hydrolysis of this tetrapeptide gave a dipeptide which contained Glu, Gly.

Deduce the primary structure of this nonapeptide. Answer

2. What force or bond which is not responsible for the primary structure of a protein is responsible for the secondary structure of a protein? Answer

3. Speaking broadly of all enzymes, briefly list three different sub-functions that portions of the enzyme might do as the enzyme performs its overall function. Answer

4. The two dimensional structures of three amino acids are given below. Draw the two dimensional structure of the tripeptide, Tyr-Glu-Leu.

Answer

| Chemistry Home | Dr. Sundin Home | Chemistry 354 | Sample Exams and Quizzes | sundin@uwplatt.edu |