H H H N, N, H H -NH2 NH H,N NH,

What is the 1-letter code for the amino acid glutamine?     N     E     Q     G

Draw the structure of Pro-Leu-Glu at physiological pH (7.4).

In each of the following pairs of amino acids, identify which amino acid would be more soluble in water: (a) Ala, Leu; (b) Tyr, Phe; (c) Ser, Ala; (d) Trp, His

LEFT:You have the following titration curve of an amino acid with a non-polar R-group with arrows on curve from (1) to (5). RIGHT: This amino acid has the following structures (a) to (e)) at different points of the titration curve. Match each numbered arrow on the curve (from (1) to (5)) with the appropriate amino acid structure (from (a) to (e)) 12 (5) H.NCHCOH + HNCHCO (a) 10 (4) CH3 CH Isoelectrin HŃCHCO + (b) ppint 43) HNCHCO CH3 CH3 (2) HaNCHCOH H. NCHCO (e) (d CH3 CH3 0.0 0.5 1.0 15 20 NaOH equivalents. H-NCHCO (e) CH3

What does this statement mean: "Upon folding of a protein many main chain amides replace their hydrogen bonds to water for those with other amide bonds"  Is this true for alpha helix in proline racemase? and is there a pattern?

List some of the possible combinations of α-helices and βsheets in supersecondary structures.

Given the polypeptide chain below: Ala-Arg-Val-His-Asp-Gln 1. What kind of polypeptide is it? 2. How many peptide bonds are there?

Draw a peptide from the given amino acids Phe-Cys-Ala-Arg-Ala-Ser-Tyr. Try to cleave this oligopeptide while it is travelling through your digestion tract.   Can someone please explain the question for me and how to draw a peptide?

Among these amino acid combinations listed above, only the combination of Lys and Glu have side chains with groups that have the greatest ability to stabilize the tertiary structure of a protein.   Explain by drawing (a) why Lys and Glu side chain interaction stabilizes the tertiary structure of a protein (b) why the pairs of Glu and Asp & Arg and Pro cannot provide the stability to the protein structure.