22. The biochemical reaction shown below represents the complete digestion or breakdown of a polymer (a large molecule as consumed in food) down to its constituent monomers, or building blocks. (A) Select two colors and COLOR the coding circles and the molecules. Then (B) answer the questions below. oieloun (b) O Monomer O Polymer asonaledue olidgoibyH.SE H. н - 5 он 1ew.ni evloralb to OH 1) oviceeib vletelgmoo ( If starch is the polymer, the monomer is: Ted n eilo eoukon @glucose b. amino acid

a. Suppose that you have the peptide Ala-Gly-Tyr-His-Leu and you treat it with FDNB and then 6M HCl. Draw the structures of all the products that you will have in solution (assume all reactions to go to completion).

25) Below are two amino acids: cysteine and histidine. a) Draw the reaction mechanism of a dehydration synthesis reaction between cysteine and histidine below: HS H Product 1 OH ox HN H b) Draw two different products of the dehydration synthesis reaction from part a). Prove that these are two different products by labelling the N and C termini, peptide bond, and R-groups of each product. Product 2 OH

2. | Calculate the overall charge (pH 7) on the following three polypeptides and answer the questions below. Assume the following pKa values: N-terminal –NH3®, 7.0; all -COOH groups, 4.0; Arg, 12.5; Cys, 8.4; His, 6.0; Lys, 10.0; Tyr, 10.0. (A) Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys–Pro–Val–Gly–Lys–Lys–Arg-Arg-Pro-Val-Lys–Val-Tyr-Pro-Asp-Ala -Gly- Glu-Asp-GIn– Ser-Ala-Glu-Ala-Phe-Pro-Leu-Arg-Glu-Phe (B) Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Ala-Pro-Val-Gly-Glu-Glu–Cys-Asp-Pro-Val-Glu–Val–Tyr-Pro-Asp- Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Phe-Pro-Leu-Glu-Phe-Cys-Ser-Tyr-Ser-Met-Glu–His-Phe-Asp-Trp-Gly- Asp-Pro-Val-Gly-Pro-Asp-Ala-Gly-Asp-Gln-Pro-Val–Gly–Glu-Glu-Cys-Asp-Pro–Val-Glu–Val–Tyr-Pro-Asp-Ala (C) Gly-Ser-Val-Arg-Asp-Pro-Val-Lys-Glu-Val-Tyr-Pro-Asp- Lys–Ala-Gly-Arg-Glu-Ser-Arg-Ala (d) Which of the three peptides would migrate the closest to the anode in isoelectric focusing? (e) Which of the above peptides would elute last from a gel filtration column? (f) Which of the three…