Chapter 3
Student: _________________________________________________________
1. Saturated fatty acids and unsaturated fatty acids differ in:
A. the number of carbon-to-carbon bonds
B. the consistency at room temperature
C. the number of hydrogen atoms present
D. all of the choices are differences between saturated and unsaturated fatty acids
2. Which of the following would NOT be a molecule used for storage?
A. starch
B. triglyceride
C. glycogen
D. chitin
3. The lipids of the cell membrane and the lipids found in butter and vegetable oil differ in which of the
following?
A. the number of fatty acids attached to the glycerol molecule
B. the glycerol molecule
C. the carbon to carbon bonds
D. lipids of the cell membrane do not have hydrophobic sections of the molecule
4. Which of the following is NOT one of the four most common elements found in living organisms?
A. hydrogen
B. oxygen
C. carbon
D. sulfur
E. nitrogen
5. Organic molecules are those that contain at least
A. carbon.
B. carbon and oxygen.
C. carbon and hydrogen.
D. carbon, oxygen, and hydrogen.
6. The differences between organic and inorganic molecules do not follow simple absolute rules. However,
most organic molecules are associated with living organisms. Which of the following statements does NOT
correspond to the general distinctions between these types of molecules?
A. Carbon dioxide (CO2) lacks hydrogen atoms found in organic molecules.
B. Formaldehyde (CH2O) is a small molecule compared to most organic molecules.
C. Salt (Na+Cl- ) is not an organic molecule but is important to the life of many organisms.
D. Because they are in living organisms, organic carbon atoms are different from the inorganic carbon atoms
forming the molecular structure of soot or a diamond.
7. A hydrocarbon is hydrophobic
A. at all times.
B. only in the living cell environment.
C. except when it has an attached ionized functional group.
D. in carbohydrates but not in lipids.
8. What term is used for molecules that have identical molecular formulas but the atoms in each molecule are
arranged differently?
A. isotope
B. isomer
C. homomolecules
D. organic
E. balanced
9. What term is based on the Greek root words for "equal" and "part"?
A. isotope
B. isomer
C. homomolecules
D. homotope
E. hydrophilic
10. Which is NOT an isomer of the other three?
A. glucose
B. ribose
C. fructose
D. galactose
11. Glucose (C6H12O6) can exist as both an open-chain form and a closed-ring form. Before 1900, glucose was
only thought to occur as an open chain. Now we know that over 99 percent of the time, glucose occurs in the
closed-ring form. What possible difference between these forms would give chemists a clue that the open-chain
form was not present?
A. Open-chain molecules can form polymers and glucose does not.
B. Only open-chain forms can undergo condensation, which does not occur with glucose.
C. An open chain presents ends with functional groups (in this case aldehyde), and glucose failed to undergo
typical aldehyde reactions; a phenomenon that could be explained by having no end functional group in a ring
structure.
D. Because glucose is solid at room temperature, it must have saturated hydrocarbon chains.
E. Glucose could not be "denatured" so it must be a tight chain.
12. Both glyceraldehyde and dihydroxyacetone have the molecular formula C3H6O3. However, the doublebonded oxygen in glyceraldehyde is attached to the end carbon while the dihydroxyacetone molecule has the
double-bonded oxygen bonded to the middle carbon.
A. These are isotopes and they will eventually decay to become the same stable molecule.
B. These are isomers and therefore have exactly the same chemical properties.
C. Both are hydrophobic hydrocarbons.
D. These molecules present different functional groups and are likely hydrophilic.
E. All of the choices are true.
13. A polysaccharide is a polymer made up of which kind of monomers?
A. simple sugars
B. amino acids
C. nucleotides
D. alternating sugar and phosphate groups
E. fatty acids and glycerol
14. A lipid is a polymer made up of which kind of monomers?
A. glucose or modified glucose molecules
B. amino acids
C. nucleotides
D. alternating sugar and phosphate groups
E. fatty acids and glycerol
15. A dehydration reaction can also be called a _________ reaction since it forms water.
A. a condensation
B. a hydrolysis
C. an isomeric
D. an energy-releasing
E. monomer formation
16. Which pair are both structural carbohydrate molecules?
A. starch and glycogen
B. starch and cellulose
C. glycogen and cellulose
D. cellulose and chitin
E. glycogen and chitin
17. Which carbohydrate is found in the cell walls of plants?
A. starch
B. chitin
C. cellulose
D. glycogen
E. glycerol
18. Which carbohydrate is used in the liver for energy storage?
A. starch
B. chitin
C. cellulose
D. glycogen
E. glycerol
19. Which carbohydrate is found in the exoskeleton of insects and crabs?
A. starch
B. chitin
C. cellulose
D. glycogen
E. glycerol
20. Which lipid does NOT contain at least some subunits similar to those in the others?
A. steroids
B. neutral fats
C. waxes
D. phospholipids
21. Which of the following lipids forms a bilayer between two watery regions, such as in the plasma membrane
of a cell?
A. steroids
B. neutral fats
C. waxes
D. phospholipids
22. Cholesterol belongs to which of the following groups?
A. steroids
B. neutral fats
C. waxes
D. phospholipids
23. If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra
tissue, which is the best molecule for storage?
A. fructose and glucose in the form of honey
B. high-calorie fat molecules
C. complex cellulose molecules
D. starch
E. glycogen with extensive side branches of glucose
24. What term is based on the Greek root words for "light" and "fat"?
A. steroid
B. glycogen
C. carbohydrate
D. cellulose
E. phospholipid
25. A protein is a polymer made up of which kind of monomers?
A. glucose or modified glucose molecules
B. amino acids
C. nucleotides
D. alternating sugar and phosphate groups
E. fatty acids and glycerol
26. A peptide bond is found in which type of biological molecule?
A. carbohydrate
B. lipid
C. nucleic acid
D. protein
27. The alpha helix and beta sheet are found at which level of protein organization?
A. primary structure
B. secondary structure
C. tertiary structure
D. quaternary structure
28. After eating eggs for breakfast, you return in the evening, dunk the dirty dishes in water, and notice the
yellow streaks remain "dried on." However, after soaking awhile, the complex of various egg yolk molecules
easily "washes off." What has happened?
A. Heating denatured the egg protein molecules, hydrolysis reactions then formed bonds in the dried egg, and
soaking in water eventually resulted in condensation reactions where water broke these bonds.
B. Heating denatured the egg protein molecules, unorganized condensation reactions then formed bonds in the
drying egg, and soaking in water eventually resulted in hydrolysis reactions where water broke these bonds.
C. The egg monomers were fused to become one polymer, which was easily dissolved by water back into
monomers.
D. The presence or absence of water changes the molecules from hydrophilic to hydrophobic respectively.
E. The addition of water converted organic molecules into inorganic molecules.
29. Below freezing and above boiling, cells are unable to function as "liquid machinery." However, most
organisms' cells are still limited from functioning throughout this full range of liquid temperatures. At the
molecular level in different organisms, cells' ability to vary in their tolerance to temperature, etc., is most
closely related to variation in
A. enzyme activity and protein denaturation.
B. ATP efficiency.
C. ability to form glucose polymers.
D. replication of nucleic acids.
E. extent of saturation of fatty acids.
30. A nucleic acid is a polymer made up of which kind of monomers?
A. amino acids
B. nucleotides
C. glucose or modified glucose molecules
D. alternating sugar and phosphate groups
E. fatty acids and glycerol
31. Which of these statements is NOT true about DNA?
A. It is the genetic material of the cell.
B. It forms a double helix.
C. Adenine pairs with thymine and guanine pairs with cytosine.
D. It contains the sugar ribose.
E. The sugar and phosphate groups form the backbone of the molecule.
32. Fish sperm consists mostly of the male fish's DNA. If we tested a sample chemically, we should find
relatively high amounts of
A. nitrogenous bases, sugar, and phosphate groups.
B. phospholipids and steroids.
C. amino acids and unsaturated fats.
D. triglycerides and ATP.
E. globular proteins and stored fats.
33. Which statement is true about RNA?
A. It contains adenine paired to thymine.
B. One of the bases from DNA is replaced by uracil.
C. It contains the sugar deoxyribose.
D. Its nucleotides contain twice as many phosphate groups as DNA's nucleotides.
E. It is a double-stranded molecule.
34. A molecule is chemically determined to have ionic bonding and a small number of atoms. This molecule is
A. inorganic in nature and most probably a part of non-living matter.
B. organic and associated with living matter.
C. hydrophobic.
D. an isotope.
35. The diversity of organic molecules is due to all of the following EXCEPT the fact that
A. carbon needs four electrons to complete its outer shell.
B. carbon can form single and double bonds with itself and other elements.
C. organic molecules always contain covalent bonds.
D. carbon can bond with as many as four other elements.
36. The reactivity of an organic molecule is primarily dependent upon ____________of the molecule.
A. the carbon skeleton
B. the attached functional groups such as an hydroxyl group
C. the isomer
D. All of the choices are correct.
37. Polymers are
A. large organic molecules linking together repeating subunits of the same type called monomers.
B. found in proteins, carbohydrates, and nucleic acids.
C. due to a dehydration reaction.
D. All of the choices are correct.
38. Which of the following is NOT a biologically active polymer?
A. starch
B. collagen
C. water
D. DNA
39. Fats, oils, and steroids are
A. proteins.
B. nucleic acids.
C. polysaccharides.
D. lipids.
40. A saturated fat is
A. solid at room temperature.
B. has fatty acids with no double bonds between the carbon atoms.
C. is of animal origin.
D. All of the choices are correct.
41. Nucleotides in a DNA molecule are joined together by peptide bonds.
LEVEL: Easy
True False
42. The secondary structure of a protein is mainly formed and held together by hydrogen bonds.
LEVEL: Intermediate
True False
43. All molecules that contain carbon are considered organic molecules.
LEVEL: Easy
True False
44. Inorganic molecules are only found in nonliving matter.
LEVEL: Easy
True False
45. Carbon contains six electrons in its outer shell.
LEVEL: Easy
True False
46. Carbon can form covalent bonds with as many as four other atoms.
LEVEL: Easy
True False
47. Carbon compounds can form rings or long chains.
LEVEL: Easy
True False
48. Hydrolysis is a process by which water is used to break apart a chemical bond.
LEVEL: Easy
True False
49. Energy is used in the process of hydrolysis.
LEVEL: Easy
True False
50. The general formula for a carbohydrate is (CH2O)n, where n is the number of groups in the molecule.
LEVEL: Easy
True False
51. Proteins may have structural and metabolic functions.
LEVEL: Easy
True False
52. Hemoglobin is a phospholipid that transports oxygen in the blood.
LEVEL: Easy
True False
53. Waxes consist of a glycerol bonded to three long-chain fatty acids.
LEVEL: Easy
True False
54. There are 20 amino acids that act as monomers for producing common proteins.
LEVEL: Easy
True False
55. Denaturation of protein, followed by renaturation in some cases, shows that it is the primary sequence of the
monomers that determines the final configuration of the molecule.
LEVEL: Intermediate
True False
56. Nucleotides are joined in a specific sequence through dehydration reactions.
LEVEL: Easy
True False
57. ATP is a protein that supplies energy to the cell.
LEVEL: Easy
True False
58. Starch is a protein that serves in energy storage in plant cells.
LEVEL: Easy
True False
59. Bases in DNA are joined by hydrogen bonding through complementary base pairing.
LEVEL: Easy
True False
60. Cholesterol is a lipid specified as a steroid.
LEVEL: Easy
True False
61. Migratory birds store energy as glycogen which is lighter than fat.
LEVEL: Easy
True False
62. The energy currency of a cell is adenosine triphosphate (ATP). ATP is chemically a lipoprotein.
LEVEL: Easy
True False
63. Why do you think small atoms are more commonly found in organic molecules rather than large ones?
64. List those characteristics of carbon that make it the most important element in organic molecules.
65. Explain the difference between hydrophilic and hydrophobic chemical interactions, and explain how these
interactions give fats and phospholipids their characteristics.
66. List an example of a hexose and a pentose sugars, and tell what kind of polymers they form.
67. Describe the differences between storage and structural carbohydrates, giving two examples of each.
68. Explain why lipids can contain so much more energy per gram than carbohydrates.
69. Explain why steroids are different in composition from other lipids and from polymers of carbohydrates,
proteins, and nucleic acids.
70. Describe the different levels of organization in proteins, and tell which is most important in the formation of
all the other levels.
71. Describe how DNA and RNA are both different from and similar to each other.
72. Chitin and cellulose are molecules that do not spontaneously break down but can be digested by bacteria
and some other microorganisms. Since carbon is not among the most common elements in the earth's crust,
what would happen if all of the chitin-digesting and cellulose-digesting organisms on the earth were destroyed?
Chapter 3 KEY
1. D
2. D
3. A
4. D
5. C
6. D
7. C
8. B
9. B
10. B
11. C
12. D
13. A
14. E
15. A
16. D
17. C
18. D
19. B
20. A
21. D
22. A
23. B
24. E
25. B
26. D
27. B
28. B
29. A
30. B
31. D
32. A
33. B
34. A
35. C
36. B
37. D
38. C
39. D
40. D
41. FALSE
42. TRUE
43. FALSE
44. FALSE
45. FALSE
46. TRUE
47. TRUE
48. TRUE
49. FALSE
50. TRUE
51. TRUE
52. FALSE
53. FALSE
54. TRUE
55. TRUE
56. TRUE
57. FALSE
58. FALSE
59. TRUE
60. TRUE
61. FALSE
62. FALSE
63. Answers will vary.
64. Answers will vary.
65. Answers will vary.
66. Answers will vary.
67. Answers will vary.
68. Answers will vary.
69. Answers will vary.
70. Answers will vary.
71. Answers will vary.
72. Answers will vary.