1. Rewind your mind
Unit 2 Biochemistry

2. The enzyme lipase breaks down lipids into which of the following molecules?
a. Sugars and glycerol
b. Fatty acids and glycerol
c. Fatty acids and amino acids
d. Amino acids and sugars

3. b. Fatty acids and glycerol

4. 2) The smallest unit of life is:
a. atoms b. tissues c. molecules d. a cell

5. d. a cell

6. 3) RNA and DNA are which type of organic compound?
a. Protein
b. Carbohydrate
c. Lipid
d. Nucleic acid

7. d. Nucleic acid

8. 4) The diagram below represents a portion of an organic molecule.
In the diagram above, what is represented by the following?
a) Simple sugar
b) Polypeptide
c) Nucleotide
d) Codon

9. c. Nucleotide

10. 5) Which are the four most abundant elements in living cells?
a. Carbon, oxygen nitrogen, sulfur
b. Carbon, oxygen, hydrogen, nitrogen
c. Carbon, oxygen, sulfur, phosphorus
d. Carbon, sulfur, hydrogen, magnesium

11. b. Carbon, oxygen, hydrogen, nitrogen

12. 6) The effect of pH on a certain enzyme is shown in the graph below
6) The effect of pH on a certain enzyme is shown in the graph below. What is the optimum pH for this enzyme?
a. Above 10
b. Between 8 & 10
c. Between 5 & 7
d. Below 5

13. b. Between 8 & 10

14. 7) Which compound represents a carbohydrate?

15. c. Glucose (C6H12O6)
elements :CHO

16. 8) Which compound represents the basic unit of both a DNA molecule and an RNA molecule?

17. b. Nucleotide (5-carbon sugar, nitrogen base, phosphate group)
elements: CHONP

18. 9) Which compound would be linked together by peptide bonds?A B C D

19. d. Amino Acid
elements: CHON

20. 10) Which compound would serve as energy storage and waterproof covering?B C D

21. a. Lipid
(shaped like letter E)
elements: CHO

22. a. Carbon b. Oxygen c. Nitrogen d. Hydrogen
11) An element found in all proteins but not in carbohydrates or lipids is
a. Carbon
b. Oxygen
c. Nitrogen
d. Hydrogen

23. c. Nitrogen

24. a. Adenine b. Cytosine c. Thymine d. Uracil
12) Which nitrogenous base is found in RNA but not in DNA?
a. Adenine
b. Cytosine
c. Thymine
d. Uracil

25. d. Uracil

26. 13) Which compounds are produced in human muscle cells as a result of the oxidation of glucose in the absence of oxygen?
a. Lipase and water
b. Sucrose and carbon dioxide
c. Ethyl alcohol and ATP
d. Lactic acid and ATP

27. d. Lactic acid and ATP

28. 14) A student tested different foods to determine which organic compounds were present. She based her results on the following information:
All four tests were performed on skim milk. The observations were that Benedict’s solution changed color and Biuret’s solution changed color. All other tests had negative results. Which organic compounds were present in skim milk?
a. starch and protein c. sugar and starch
b. sugar and protein d. fat and sugar

29. b. sugar and protein

30. 15. Strawberry plants are producers (autotrophs)
15. Strawberry plants are producers (autotrophs). One structural component of their cells is a molecule called cellulose. Which of the following best describes the molecule cellulose?
a. Carbohydrate b. Fatty acid
c. Cytoplasm d. Enzyme

31. a. Carbohydrate

32. 16) Animals commonly store energy in the form of
a. Fats and glycogen b. Minerals and water
c. Waxes and oils d. Water and lipids

33. a. Fats and glycogen

34. 16) Which organic compound is correctly matched with the subunit that composes it?
a. Cellulose- amino acid
b. Starch- glucose
c. Protein- fatty acid
d. Lipid- nucleic acid

35. b. Starch- glucose

36. 17) All of the following are functions of proteins EXCEPT:
Act as enzymes
b) Regulate the body through homeostasis
c) Store the genetic information of the cell
d) Build and repair muscles and bones

37. c) Store the genetic
information of the cell

38. a) A nucleotide contains a 5-carbon sugar.
18) How is the structure of a carbohydrate similar to that of a nucleic acid?
a) A nucleotide contains a 5-carbon sugar.
b) Both structures are very complex.
c) The structure of both a carbohydrate and a nucleic acid allow them to carry a great amount of energy between bonds.
d) A nucleic acid is the building block of a carbohydrate.

39. a) A nucleotide contains a 5-carbon sugar.

40. 19) Mariah is trying to convince her best friend that the function of a protein is important to a carbohydrate. Which of the following statements could she use to explain the relationship between the two organic molecules?
a) Both proteins and carbohydrates provide energy.
b) Specific proteins called enzymes break down
carbohydrates to release quick energy.
c) Antibodies are proteins that protect the body from harmful substances, such as carbohydrates.
d) Proteins produce all of the carbon, hydrogen and oxygen make up a carbohydrate.

41. b) Specific proteins called enzymes break down
carbohydrates to release quick energy.

42. 20) The chart below describes four classes of compounds.
Characteristic A
Glycerol is a building block B
Contains amino acids C
Formed from subunits contain a nitrogen base, a phosphate and ribose D
Includes starches
20) The chart below describes four classes of compounds.
What is another characteristic of the compound in class B?
a) They are composed of basic subunits known as nucleotides.
b) They also include sugars.
c) They transfer amino acids to ribosomes during protein synthesis.
d) They include compounds such as insulin, antibodies, and hemoglobin.

43. d) They include compounds such as insulin, antibodies, and
hemoglobin.

44. 21) The picture above depicts a _____________ because it is made of _____________.
a) Carbohydrate; sugars and starches
b) Nucleic acid; a sugar, base, and phosphate group
c) Lipid; fatty acids and glycerol
d) Protein; amino acids

45. b) Nucleic acid; a sugar,
base, and phosphate group

46. 22) Enzymes are said to be specific because they:
Work at only one temperature
Work at only one pH
Catalyze only certain reactions
Are lipids with special functions

47. Catalyze only certain reactions

48. 23) The diagram below represents a series of reactions that can happen in an organism.
This diagram best illustrates the relationship between
Enzymes and synthesis
Amino acids and glucose
Antigens and immunity
Enzymes and ribosomes

49. Enzymes and synthesis

50. Hydrogen peroxide + Catalase  Water + Oxygen + Catalase
24) Catalase is an enzyme that causes the following reaction:
Hydrogen peroxide + Catalase  Water + Oxygen + Catalase
What is the best explanation for catalase being present on both the reactant and the product side of the reaction?
a) Enzymes are substrate specific
b) Enzymes are reusable
c) Enzymes speed up chemical reactions
d) Enzymes are affected by such factors as pH

51. b) Enzymes are reusable

52. a) They are not reusable b) They have combined with another enzyme
25) Why do most enzymes not function properly after being exposed to high temperatures?
a) They are not reusable
b) They have combined with another enzyme
c) Their active site has been changed
d) Their water content has been reduced

53. c) Their active site has been changed

54. 26) Base your answer to the following question on the graph below.
What is the optimum temperature for the enzyme?
)0 °C C) 55 °C
)37 °C D) 60 °C

55. B)37 °C

56. 27) The diagram below represents a biochemical
process that occurs in organisms.
The substance labeled “catalyst” is also known as
A hormone C. A substrate
An enzyme D. An inorganic compound

57. B) An enzyme

58. d) Large intestine (pH 9)
29) The graph indicates that trypsin would function best
in which environment?
a) Mouth (pH 6.5)
b) Small intestine (8)
c) Stomach (pH 2.5)
d) Large intestine (pH 9)

59. b) Small intestine (8)

60. 30) Pepsin and trypsin are enzymes so they are classified as
a) Carbohydrates b) Proteins
c) Lipids d). Nucleic Acids

61. b) Proteins

62. 31) The graph below shows the change in the
growth of the plant. Which of the following
best explains this?
A)The enzymes for photosynthesis work optimally at about 18°C.
B)When plants reach 24°C or higher, their enzymes no longer work because it is too hot
C)Temperature has no affect on plant growth
D)The enzymes used during photosynthesis are denatured at about 18°C

63. A)The enzymes for photosynthesis
work optimally at about 18°C.

64. 33) In the diagram above which of the following letter represents
the substrate?
a. A b. B c. C d. D

65. A) Substrate

66. 34) Individuals who lack lactase are unable to break down the sugar
lactose. Which term best describes lactase?
a. enzyme b. fatty acid c. lipid d. starch

67. a. enzyme

68. 35) Which of the following environmental factors would likely
increase an enzymes function?
a. a change in salinity c. decreasing temperature
b. creating optimal conditions d. decreasing pH

69. b. creating optimal conditions

70. 36) When an enzyme loses its shape, it also loses its function.
The enzyme is said to be:
a. denatured b. inactivated c. primed d. activated

71. a. denatured

72. 36) Enzymes only work with specific substrates because each substrate —
a. actively interferes with other substrates around it
b. destroys its specific enzyme
c. has the correct shape to fit with the enzyme’s active site
d. inhibits the enzymes function

73. c. has the correct shape to fit with the enzyme’s active site

74. a. Enzymes increase the energy required for a reaction to occur.
37) . How do enzymes speed up biological chemical reactions?
a. Enzymes increase the energy required for a reaction to occur.
b. Enzymes decrease the energy required for a reaction to occur.
c. Enzymes have no affect on the energy required for a reaction to occur.
d. Enzymes maintain the energy needed for a reaction to occur.

75. b. Enzymes decrease the energy required for a reaction to occur.

76. catalyst because it causes the reaction to — a. slow down b. speed up
38) According to the graph, adding the enzyme amylase acts as a
catalyst because it causes the reaction to —
a. slow down
b. speed up
c. take in heat
d. give off heat

77. b. speed up

78. instead of proteins before a race?
39) Why would a distance runner consume carbohydrates
instead of proteins before a race?
a. Carbohydrates provide insulation for heat.
b. Carbohydrates provide structure for tissues.
c. Carbohydrates provide genetic material for muscle cells.
d. Carbohydrates provide energy for endurance.

79. d. Carbohydrates provide energy for endurance.

80. c. Paper bag d. All would test positive
40) Which of the following would NOT test positive for steak?
Benedict’s b. Biuret
c. Paper bag d. All would test positive

81. a) Benedict’s.

82. a. Enzymes b. Structure c. Energy d. Communication
41) Which of the following is NOT a MAIN function of proteins?
a. Enzymes b. Structure c. Energy d. Communication

83. b. Structure

84. a. amino acids b. nucleotides c. monosaccharides d. triglycerides
42) Carbohydrates are made of small subunits called:
a. amino acids b. nucleotides c. monosaccharides d. triglycerides

85. c. monosaccharides

86. instead used by cells for quick energy?
43) Which of the following is NOT a LARGE carbohydrate, but is
instead used by cells for quick energy?
a. glucose b. cellulose c. glycogen d. starch

87. a. glucose

88. 45) Which of the following is correctly matched?
a. atoms are made of molecules
b. macromolecules are made of polymers
c. subunits are made of polymers
d. polymers are made of subunits

89. d. polymers are made of subunits

90. 46) Which of the following is correctly matched?
a. atoms are made of molecules
b. macromolecules are made of polymers
c. subunits are made of polymers
d. polymers are made of subunits

91. d. polymers are made of subunits

92. a. inorganic b. organic c. elements d. cells
47) Lipids, proteins and nucleic acids are considered ____________ because they contain C,H,O.
a. inorganic b. organic c. elements d. cells

93. b. organic

94. a. Benedict’s b. Biuret c. Iodine d. Paper bag
48) Which of the following would NOT test positive for sweet potatoes fries?
a. Benedict’s b. Biuret c. Iodine d. Paper bag

95. b. Biuret

96. amino acids b. nucleotides c. monosaccharides d. triglycerides
49) Lipids are made of small subunits called:
amino acids b. nucleotides c. monosaccharides
d. triglycerides

97. d. triglycerides

98. amino acids b. nucleotides c. monosaccharides d. triglycerides
50) Nucleic acids are made of small subunits called:
amino acids b. nucleotides c. monosaccharides
d. triglycerides

99. b. nucleotides

100. amino acids b. nucleotides c. monosaccharides D. triglycerides
52) Proteins are made of small subunits called:
amino acids b. nucleotides c. monosaccharides
D. triglycerides

101. amino acids