Name:_____________

Chem 150 Practice Exam #3

Exam 3

Directions: 1. Do not open the exam until you are told to do so.

2. Select only ONE choice for each problem and blacken or fill in the choice with a pencil (NOT ink pen). Selecting more than one choices or no selection for a problem will be counted wrong.

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CHEM 150, EXAM 3: May 6, ’05 Name:__________________

Ch. 8 Lipids:1. In which solvent would lipids be most soluble? a

a. hexane b. water c. methyl alcohol d. ethyl alcohol

2. Inspect the molecules below and answer the questions that refer to these molecules. Molecules like these are classified as _______ . b

a. triglyceridesb. fatty acidsc. waxesd. phospholipidse. none of the above

3. Molecule “B” in question #2 above can be referred to as _____ . da. stearic acid b. lauric acid c. Oleic acid d. -3 fatty acid e. none of the above

4. Refer to question #2. Molecules B, C and D are said to be ________ . ba. saturated b. unsaturated c. completely hydrophobic d. completely hydrophilic

5. Because of the properties in portion A and portion B, the molecule below is said to have ______ properties. d

a. hydrophobic b. lipophobicc. hydrophilic d. amphipathic

6. The structure CH3(CH2)12CH2COOCH2(CH2)24CH3 is best classified as a _____, b

a. triglyceride b. wax c. steroid d. phospholipid e. none of the above

7. The steroid compound that is the source for the production of other steroid hormones is ____ . c

a. arachidonic acid b. triglyceride c. cholesterol d. phospholipids

8. The steroid compound that is believed to be used for maintaining the correct degree of cell membrane rigidity is ____ . d

a. arachidonic acid b. triglyceride c. sphingolipid d. cholesterol

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Use the molecules in question #9 to answer questions # 9 – 11:9. Which molecule is glycerophospholipid? Note: R’s represent long carbon chains. b

a. Ab. Bc. Cd. none of the above

10. Which molecule is a lipid called sphingomyelin. ca. A b. B c. C d. none of the above

11. Which compounds form the cell membrane? da. A only b. B only c. C only d. B and C only e. none of the above

12. Which molecule makes up oil? (Use the A, B and C as your answer choices.) c

13. Refer to question #12. Which molecule contains the fatty acyl groups of palmitic acid, stearic acid, and myristic acid? ba. A only b. B only c. C only d. both A and B e. none of the above

14. The effect of the hydrogenation of oils is to _____. aa. remove double bonds, increasing the degree of saturation.b. cause the oils to remain as liquids, increasing the C=C bonds.c. make the oils boil at a lower temperatured. make the oils oxidize

15. Shown below is the structure of estradiol. It belongs to what class of lipids? d

a. phospholipidsb. eicosanoidsc. triglyceridesd. steroids

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16. Estradiol is considered to be a __________ hormone. aa. human female b. human male c. plant d. potato hormone

17. Shown below is a picture of the lipid bilayer of the cell membrane. The tails of the lipids face each other because they are _____ . a

a. hydrophobic b. hydrophilicc. amphipathic d. amphoteric

18. This compound is a ______ . c

a. glycerolphospholipid b. sphingomyelinc. glycolipid d. triglyceride

19. What is the function of HDL? aa. transport cholesterol and phospholipids from cells to liver.b. transport cholesterol and phospholipids from liver to cells.c. digest cholesterol and phospholipids in cells.d. digest cholesterol and phospholipids in liver._ _ _ _Ch. 12 Carbohydrates:20. Which is the structure of glucose? d

21. The monosaccharide below is a(n) _____ . b

a. purineb. aldosec. enantiomerd. ketosee. glycolysis

22. Which molecule contains the pyranose ring? a

c). none of the above

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23. Which molecule below is an aldohexose? a

24. Molecules II and IV are a pair of ________ . a

a. enantiomers b. cis-trans isomers c. identical moleculesd. anomers e. none of the above

25. Which is the structure of -D-glucose? c

a. A b. B c. C d. D e. none of the above

26. Which is the structure of α-D-galactose? (Look up the structure on a sheet.) B

A B

27. The structure of -D-ribose is shown below. Identify the anomeric carbon or hemiacetal carbon in -D-ribose. a

a. 1 onlyb. 2 and 3c. 3 and 4d. 1, 2 and 3e. 1, 2, 3, and 4

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28. If a molecule of sucrose is hydrolyzed (broken down to monosaccharides), what would be the monosaccharides found in the products? (Note: Do not consider the - or -forms). c

a. two molecules of fructose b. one lactose and one glucosec. one glucose and one fructose d. one galactose and one glucosee. one fructose and one galactose

29. If a molecule of maltose is hydrolyzed, what would be the monosaccharides found in the products? (Note: Do not consider the - or -forms). c

a. two molecules of fructose b. one fructose and one galactosec. two molecules of glucose d. one lactose and one glucosee. none of the above

30. If a molecule of lactose is hydrolyzed, what would be the monosaccharides found in the products? (Note: Do not consider the - or -forms). aa. one glucose and one galactose b. one maltose and one fructosec. one fructose and one galactose d. one fructose and one glucosee. none of the above

31. Olestra is composed of a disaccharide and several fatty acyl groups. What disaccharide is contained in the Olestra molecule? a. lactose b. maltose c. sucrose d. cellobiose e. none of the above

32. Which molecule possesses the (14) glycosidic bond? b

a. A only b. B only c. both A and B

Use the picture below to answer questions # 33 - 34.

33. The molecule shown to the right can be classified as a(n) ___ . ba. monosaccharide b. disaccharide c. polysaccharide d. dipeptide e. none of the above

34. The glycosidic bond present on this molecule is _____ . ca. (14) b. (14) c. (16)d. (12) e. 16

35. What type of polysaccharide is shown below? a

a. amyloseb. cellulosec. amylopectind. glycogene. starch

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36. What is the biological role of amylopectin? ca. provide structural rigidity in plants b. provide structural rigidity in animalsc. provide energy or energy storage in plants d. provide energy or energy storage in animalse. form bile salts

37. What is the biological role of glycogen? d

a. provide structural rigidity in plants b. provide structural rigidity in animalsc. provide energy or energy storage in plants d. provide energy or energy storage in animalse. form cell membranes

38. What polysaccharide provides structural protection to insects or crustaceans? e

a. Cellulose b. amylose c. amylopectin d. glycogen e. chitin

39. How is the structure of cellulose different from that of amylose? ba. Cellulose has α(14) glysidic bond, but amylose has (14) glysidic bond.b. Cellulose has (14) glysidic bond, but amylose has α(14) glysidic bond.c. Cellulose has no branches, but amylose has brances.d. Cellulose has branches, but amylose has no brances.

40. How is the structure of glycogen different from that of amylopectin? ca. Glycogen has (14) and α(16) glycosidic bonds, but amylopectin has (14) bonds.b. Amylopectin has more frequency of branching than glycogen.c. Glycogen has more frequency of branching than amylopectin.d. Glycogen has α(14) and α(16) glycosidic bonds, but amylopectin has (14) bonds.

41. What type of glycosidic bond is present on this polysaccharide found in certain types of lichens? d

a. α(14)b. (14)c. α(16)d. (16)e. none of the above

Ch. 13: Amino acids51. The side chain of the amino acid

phenylalanine is shown here. The side chain is classified as _____. a

a. nonpolarb. polar-acidicc. polar-basicd. polar-neutral

52. The side chain of the amino acid histidine is shown here. The side chain is classified as _____. c

a. nonpolarb. polar-acidicc. polar-basicd. polar-neutral

53. Shown here is the amino acid alanine at a pH of _____. c

a. 1b. 14

54. Shown here is the amino acid alanine at a pH of _____. b

a. 1b. 14c. neutral pH

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c. neutral pHd. both (a) and (c)

d. both (a) and (c)

55. The side chains of which pair of amino acids can form a salt bridge? Note: Look up the amino acid structure sheet. ca. Glycine and Aspartic acid b. Glutamic acid and Aspartic acidc. Lysine and Glutamic acid d. Alanine and Leucinee. none of the above

56. A zwitterion is an _____. ca. ion that is polar acidic. b. ion that is polar basic.c. ion that has both positive and negative charge. d. ion that is polar neutral.

Use this molecule to answer questions #57 – 59:

57. This molecule can be classified as a(n) _____ . ca. polysaccharide b. polypeptide c. hexapeptide d. protein

58. What is the amino acid sequence of this molecule? ba. Pro-Ser-Asp-Gly-Lys-Glyb. Gly-Lys-Gly-Asp-Ser-Proc. Gly-Arg-Gly-Asp-Ser-Prod. Pro-Ser-Glu-Gly-Lys-Glye. none of the above

59. The N-terminus amino acid residue is ______ . ba. Proline b. Glycinec. Lysine d. Aspartate

60. The denaturing of a protein can be caused by _____. d

a. heatingb. exposing to detergentsc. changing the pHd. All of these can cause

denaturation

61. Which picture below best represents the structure of the Hemoglobin molecule? Note: Each circle represents a subunit. c

62. Enzymes are _____ . aa. proteinsb. polysaccharidesc. lipidsd. inorganic compoundse. coordination compounds

63. Circle all the chiral carbon atoms on this molecule. This is testing on the concept of chirality. e

a. 4 and 5b. 4, 5, 9, and 11c. 2, 3, 7, 9, and 11

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d. 3, 4, 5, 6, 8 and 17e. 3, 4, 5, and 7

64. Evaluate this statement and see what level of protein structure it describes. “The polypeptide chain has a number of bends and twists which result in compacting it into a ball-like unique three-dimensional shape.” c

a. primary structure b. secondary structure c. tertiary structured. quaternary structure e. none of the above

65. The α-helix and β-pleated sheet are both forms of the _____ structure of proteins. ba. primary b. secondary c. tertiary d. quaternary

Use the picture below for questions # 66 - 69:

66. On the structure of the protein above, the non-covalent interaction labeled by arrow “A” is called ______ . da. salt bridge b. hydrogen bond c. disulfide bond d. hydrophobic interactione. none of the above

67. On the structure of the protein above, the non-covalent interaction labeled by arrow “B” is called ______ . aa. salt bridge b. hydrogen bond c. disulfide bond d. hydrophobic interactione. none of the above68. Which arrow points to a region that has the-sheet structure? da. A b. B c. C d. D e. E

69. Which arrow points to a region that has the α-helical structure? ea. A b. B c. C d. D e. E

70. What would happen to the non-covalent interaction in the protein structure below if the Lysine side chain is replaced with a Glutamic acid side chain (-CH2CH2COO-)? c

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D

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a). The non-covalent interaction shown would remain intact.b). The protein structure would be broken down to individual amino acids.c). The ionic interaction would be broken and cause the protein to lose its unique structure.d). Hydrogen bond would be formed between the -CH2CH2COO- and –OOCCH2- side chains, and the protein structure would remain the same.

71. On the picture below, what does Z represent? a

a. Z = enzyme b. Z = substratec. Z = products d. Z = inhibitor_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 72. What is the effect of X upon binding or fitting into one of the pocket on Z in question #71? ca. stimulation of product formation (Product formed faster).b. has no effect.c. inhibition of product formation.d. X turns into product.

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