L07 Chem 481 Lecture Notes - Lecture 5: Glyceraldehyde, Isoelectric Point, Selenocysteine

34. Which of the following amino acids can coordinate to a metal ion? a. arginineb. glutamic acid c. isoleucine d. phenylalanine 35. Which of the following denaturing agents affects hydrophobic regions? a. detergents c. heavy metals b. heat d. urea 36. Which of the following pairs of amino acid s can form hydrogen bonds? a. alanine and glutamic acid c. leucine and phenylalanine b. aspartic acid and lysine d. serine and tyrosine 37. How many amino acids have an amide side chain? c. 3 d.4 38. Which of the following is true of the isoelectric point of amino acids? a. The isoelectric points of all amino acids are the same. b. It is the pH at which an amino acid conducts electricity c. It is the pH at which an amino acid has equal numbers of positive and negative charges. d. All of the above are true 39. Antiparallel β-sheets have t progress from N to C termini in the same direction. a. sheets that b. usually all of their hydrophobic residues on one side of the sheet. c. all hydrophobic residues. d. all hydrophilic residues e. fibers that can be stretched or extended, but are not flexible 40. Alpha helices are stabilized primarily by: a. hydrogen bonds between the main chain peptide bond component atoms. b. electrostatic interactions between R-groups c, hydrophobic interactions between the α-carbons of the main chain. d. hydrogen bonding between the R-groups. e. hydrophobic interactions between R -groups and the solvent water . An electrostatic interaction might occur within a protein between which of the following amino acid pairs at typical physiological pH? a. Ser/Asın b. Asp/Glu c. Arg/Cys d. Lys/Asp e. Val/lle

26. Which of the following is true of the solubility of proteins in water? a Both fibrous and glcbular proteins are generally insoluble in water b. Bot fibrous and globular proteins are generally soluble in water Fibrous proins agenerally inscluble in water d. Globular proteins are generally insoluble in water 27. Which statement about the properties of a protein-protein interaction is not true? a. Reflects the conposition of protein surfaces, rather than the proteir core b. Enriched in hydrophobic rcsiducs, particularly in aromatic residucs c. Protein-proein interaction interfaces are dynamic and frequertly planar d. Exhibit both shape e. all of thern are truc and electrostatie complementarity 28. Ilow many chiral carbons are present in the open-chain form of an aldopentose? a. 2 b.3 29 When glucose adopts a pyranose structure which carbon is the anomeric carbon? 30 The cyclic structuics of monosaccharides are which of the following? a, acetals b. hemiacetals c. ethers d. esters 31. Which of the following side chains are hydrophilic? a, acidic b. basic c, polar but neutrad. all ofthese 32. Which of the following amino acids will exist as a -2 ion at very high pH? a. arginine c, isoleuc ine b. glatamic acid d. none of these 33. Which of the ollowing is serylalanine NH-CH-CNH CH NH, CHC-NH-CH CH, CH OH NH-CH-C-NH-ÇH-CONH-CH-C-NH-CH-CO CH, CH,OH CH,