Multiple Choice

1. The simplest units of matter are:
A. protons.
B. electrons.
C. neutrons.
D. atoms.
E. molecules.

Answer: D
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

2. When two hydrogen atoms bind with two oxygen atoms, the result is:
A. water.
B. hydrogen peroxide.
C. hydrogen molecules.
D. synthesis reactions.
E. decomposition reactions.

Answer: B
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

3. If the atomic number of an element is 8, how many protons does the element contain?
A. 4
B. 6
C. 8
D. 10
E. 12

Answer: C
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

4. Substances that release ions in water are called:
A. catalysts.
B. elements.
C. electrons.
D. electrolytes.
E. atoms.

Answer: D
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

5. Ions with a positive charge are referred to as:
A. cations.
B. anions.
C. atoms.
D. electrolytes.
E. compounds.

Answer: A
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

6. The most abundant compound in the human body is:
A. calcium.
B. water.
C. protein.
D. oxygen.
E. fat.

Answer: B
Subject: Biochemistry, Chapter 2
Complexity: Easy

7. Steroid molecules are large molecules of:
A. lipids.
B. carbohydrates.
C. proteins.
D. nucleic acid.
E. water-soluble vitamins.

Answer: A
Subject: Biochemistry, Chapter 2
Complexity: Easy

8. Chemicals that resist pH changes are called:
A. bases.
B. acids.
C. enzymes.
D. buffers.
E. catalysts.

Answer: D
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

9. Isotopes of an element differ in the number of:
A. neutrons in the nucleus.
B. electron clouds.
C. protons in the nucleus.
D. electrons in the nucleus.

Answer: A
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

10. Glycerol contains how many molecules of fatty acids?
A. 1
B. 2
C. 3
D. 4
E. 5

Answer: C
Subject: Biochemistry, Chapter 2
Complexity: Easy

11. An atom’s mass is determined mostly by the number of:
A. protons.
B. neutrons.
C. electrons.
D. isotopes.
E. protons and neutrons.

Answer: E
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

12. Which of the following is not an example of an organic substance?
A. Lipids
B. Nucleic acid
C. Bicarbonate
D. Protein
E. Carbohydrate

Answer: C
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

13. The atomic weight of an element’s atom equals the number of:
A. electrons and protons.
B. electrons and neutrons.
C. protons and neutrons.
D. protons, electrons, and neutrons.
E. None of these is correct.

Answer: C
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

14. Which of the following is the largest in size?
A. A proton
B. A neutron
C. An electron
D. An atom
E. A molecule

Answer: E
Subject: Molecules and Compounds, Chapter 2
Complexity: Moderate

15. Which of the following indicates the atomic number of an atom?
A. Protons and electrons in the atom
B. Protons and neutrons in the nucleus
C. Protons in the nucleus
D. Neutrons in the nucleus
E. Electrons in the outer shells

Answer: B
Subject: Atomic Structure, Chapter 2
Complexity: Moderate

16. The substances present in a mixture in smaller amounts are called:
A. solutes.
B. colloids.
C. solvents.
D. diluents.
E. sol-gels.

Answer: A
Subject: Solutions, Chapter 2
Complexity: Moderate

17. Which of the following occurs in an ionic bond?
A. Two or more atoms lose electrons at the same time.
B. Hydrogen forms bonds with negatively charged atoms in the same or different molecule.
C. Atoms share electrons.
D. Electrons are transferred from one atom to another.
E. A pair of electrons is shared unequally by two atoms.

Answer: D
Subject: Ionic Bonds, Chapter 2
Complexity: Moderate

18. Which of the following is created between two atoms when a pair of electrons is unequally shared?
A. Hydrogen bond
B. Polar covalent bond
C. Double covalent bond
D. Single covalent bond
E. Triple covalent bond

Answer: B
Subject: Polar and Nonpolar Molecules, Chapter 2
Complexity: Moderate

19. Water is a polar molecule with two poles of charge. Which of the following best describes these two poles?
A. Surface tension
B. A double bond
C. A dipole
D. Radical
E. Covalent

Answer: C
Subject: Polar and Nonpolar Molecules, Chapter 2
Complexity: Moderate

20. Which of the following is an example of a suspension?
A. Salt water
B. Alcohol
C. Urine
D. Cytoplasm
E. Blood

Answer: E
Subject: Suspensions, Chapter 2
Complexity: Moderate

21. Which of the following is not an example of an inorganic compound?
A. Salt
B. Glucose
C. Water
D. Base
E. Acid

Answer: B
Subject: Inorganic Substances, Chapter 2
Complexity: Moderate

22. Which of the following is the body’s most readily available source of energy?
A. Proteins
B. Water
C. Lipids
D. Carbohydrates
E. Nucleic acids

Answer: D
Subject: Carbohydrates, Chapter 2
Complexity: Moderate

23. Which of the following is the most important metabolic fuel molecule in the body?
A. Glucose
B. Protein
C. Sucrose
D. Starch
E. Vitamins

Answer: A
Subject: Polysaccharides, Chapter 2
Complexity: Moderate

24. Which of the following is the storage carbohydrate of animal tissues?
A. Glucose
B. Sucrose
C. Glycogen
D. Fructose
E. Cellulose

Answer: C
Subject: Polysaccharides, Chapter 2
Complexity: Moderate

25. Which of the following lipids is the most abundant in the plasma?
A. Triglycerides
B. Phospholipids
C. Steroids
D. Cholesterol
E. Lipoproteins

Answer: E
Subject: Lipids, Chapter 2
Complexity: Moderate

26. Which of the following statements is true regarding lipids?
A. They provide roughly twice the energy of carbohydrates.
B. They contain the genetic information found in cells.
C. They are composed of C, H, O, and N atoms.
D. They are integral molecules of the nucleus membrane.
E. They form the regulatory molecules known as enzymes.

Answer: A
Subject: Lipids, Chapter 2
Complexity: Moderate

27. Which of the following types of lipids is mostly derived from arachidonic acid existing in all cell membranes and is involved in blood clotting and contractions during labor?
A. Triglyceride
B. Monoglyceride
C. Steroid
D. Prostaglandin
E. Glycolipid

Answer: D
Subject: Eicosanoids, Chapter 2
Complexity: Difficult

28. Glycoproteins are combinations of proteins and which of the following?
A. Lipids
B. Carbohydrates
C. Fatty acids
D. Steroids
E. Nucleic acids

Answer: B
Subject: Proteins, Chapter 2
Complexity: Easy

29. Each amino acid differs from other organic substances regarding which of the following?
A. Number of peptide bonds in the molecule
B. Number of central carbon atoms
C. Number of carboxyl groups
D. Size of the amino group
E. Nature of the R group

Answer: E
Subject: Proteins, Chapter 2
Complexity: Difficult

30. Which of the following is not an example of globular proteins?
A. Protein-based hormones
B. Fibrous proteins
C. Antibodies
D. Enzymes
E. Collagens

Answer: B
Subject: Types of Proteins, Chapter 2
Complexity: Moderate

31. Which of the following is the structural unit of nucleic acids?
A. Purines
B. Pyrimidines
C. Nucleotides
D. Fatty acids
E. Amino acids

Answer: C
Subject: Nucleic Acids (DNA and RNA), Chapter 2
Complexity: Moderate

32. When atoms complete their outer electron shells by sharing electrons, they form which of the following?
A. Cations
B. Anions
C. Ionic bonds
D. Hydrogen bonds
E. Covalent bonds

Answer: E
Subject: Covalent Bonds, Chapter 2
Complexity: Moderate

33. If an isotope of lithium has 3 protons, 4 neutrons, and 3 electrons, its atomic weight is:
A. 4.
B. 6.
C. 7.
D. 10.
E. 16.

Answer: C
Subject: Atomic Structure, Chapter 2
Complexity: Moderate

34. Which of the following is the most important high-energy compound in cells?
A. Ribonucleic acid
B. Deoxyribonucleic acid
C. Adenosine diphosphate
D. Adenosine monophosphate
E. Adenosine triphosphate

Answer: E
Subject: Adenosine Triphosphate, Chapter 2
Complexity: Moderate

35. The formula AB  A + B is to decomposition as the formula A + B  AB is to which of the following?
A. Replacement
B. Combustion
C. Synthesis
D. Metabolism
E. Exchange

Answer: C
Subject: Synthesis Reactions, Chapter 2
Complexity: Moderate

36. Which of the following pH levels is closest to neutral pH?
A. 2
B. 6
C. 4
D. 5
E. 3

Answer: B
Subject: Acids, Bases, and the pH Scale, Chapter 2
Complexity: Moderate

37. Which of the following elements is the most plentiful in the human body?
A. Carbon
B. Potassium
C. Sulfur
D. Oxygen
E. Sodium

Answer: D
Subject: Elements of the Human Body, Chapter 2
Complexity: Moderate

38. Which of the following is true about ribonucleic acid (RNA)?
A. It contains the cell’s genetic information
B. It is restricted to the nucleus.
C. It contains the pyrimidine uracil in place of thymine.
D. It is double stranded.
E. It contains the pentose deoxyribose.

Answer: C
Subject: Characteristics of DNA and RNA, Chapter 2
Complexity: Difficult

39. Which of the following elements is the second most abundant in the human body?
A. Carbon
B. Calcium
C. Oxygen
D. Hydrogen
E. Phosphorus

Answer: A
Subject: Elements of the Human Body, Chapter 2
Complexity: Moderate

40. Which of the following is the product formed from the phosphorylation of ADP?
A. Ribose
B. Deoxyribonucleic acid
C. Adenosine diphosphate
D. Adenosine triphosphate
E. Adenine

Answer: D
Subject: Adenosine Triphosphate, Chapter 2
Complexity: Difficult

41. Which of the following would be the result of this formula: ADP + P?
A. DNA
B. ATP
C. ADP
D. 2 ADP
E. Adenine

Answer: B
Subject: Adenosine Triphosphate, Chapter 2
Complexity: Difficult

42. In hydrolysis reactions, compounds react with and result in which of the following?
A. Water, causing synthesis
B. Carbon, causing decomposition
C. Hydrogen, causing decomposition
D. Glucose, causing decomposition
E. Water, causing decomposition

Answer: E
Subject: Disaccharides, Chapter 2
Complexity: Moderate

43. Proteins, carbohydrates, and lipids are classified as which of the following?
A. Bases
B. Acids
C. Salts
D. Organic molecules
E. Inorganic molecules

Answer: D
Subject: Organic Substances, Chapter 2
Complexity: Moderate

44. A nucleotide consists of which of the following?
A. A nitrogen base, a pentose sugar, and a phosphate group
B. A five-carbon sugar and an amino acid
C. A five-carbon sugar and a phosphate group
D. A five-carbon sugar and a nitrogenous base
E. A phosphate group and a nitrogen base

Answer: A
Subject: Nucleic Acids (DNA and RNA), Chapter 2
Complexity: Moderate

45. Which of the following is a polysaccharide formed in the liver and in the muscles?
A. Fructose
B. Starch
C. Glycogen
D. Cellulose
E. Sucrose

Answer: C
Subject: Polysaccharides, Chapter 2
Complexity: Moderate

46. Which of the following substances would be the least acidic?
A. White wine, pH = 3
B. Stomach secretions, pH = 1
C. Lemon juice, pH = 2
D. Urine, pH = 6
E. Tomato juice, pH = 4

Answer: D
Subject: Acids, Bases, and the pH Scale, Chapter 2
Complexity: Moderate

47. A triglyceride consists of which of the following?
A. Amino acids that have been thoroughly saturated with hydrogen
B. One glycerol molecule bonded to three fatty acid molecules
C. A sugar-phosphate backbone attached to two amino acid groups
D. Two or more hexoses
E. Two or more pentoses

Answer: B
Subject: Triglycerides, Chapter 2
Complexity: Moderate

48. Enzymes are organic catalysts that:
A. determine the nature of the products of a reaction.
B. are essential raw materials for a chemical reaction and are converted into some of its products.
C. alter the direction in which a chemical reaction proceeds.
D. increase the speed of a chemical reaction.
E. increase production of vitamin D in the liver.

Answer: D
Subject: Enzymes, Chapter 2
Complexity: Moderate

49. Which of the following are examples of structural lipids?
A. Eicosanoids and lipases
B. Cholesterol and phospholipids
C. Unsaturated fats and nucleic acids
D. Saturated fats and lipoproteins
E. Triglycerides and carbohydrates

Answer: B
Subject: Phospholipids and Steroids, Chapter 2
Complexity: Moderate

Fill-in-the-Blank

50. Ions with a positive charge are called __________.

Answer: cations
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

51. The chemical bond between atoms that share electrons is called a(n) __________ bond.

Answer: covalent
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

52. Hydrogen ion concentrations can be measured by a value called __________.

Answer: pH
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

53. Atoms normally contain an equal number of protons and __________.

Answer: electrons
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

54. Enzymes promote chemical reactions by lowering the activation __________ requirements.

Answer: energy
Subject: Biochemistry, Chapter 2
Complexity: Easy

55. AB+CD→AD+CB is an example of a(n) __________ reaction.

Answer: exchange
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

56. Phospholipids are an important part of __________ structures.

Answer: cell
Subject: Biochemistry, Chapter 2
Complexity: Easy

57. Radiation is basically identified as one of three common forms: alpha, beta, or __________.

Answer: gamma
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

58. Inorganic compounds do not contain __________ as the primary structural atom.

Answer: carbon
Subject: Biochemistry, Chapter 2
Complexity: Moderate

59. The __________ contains approximately the entire mass of the atom.

Answer: nucleus
Subject: Atomic Structure, Chapter 2
Complexity: Moderate

60. An example of a nonliving colloid that undergoes a sol-gel transformation is a gelatin product such as __________.

Answer: Jell-O
Subject: Colloids, Chapter 2
Complexity: Easy

61. The center of an atom is called the __________.

Answer: nucleus
Subject: Atomic Structure, Chapter 2
Complexity: Easy

62. A(n) __________ is a homogeneous mixture containing a solvent and a solute.

Answer: solution
Subject: Solutions, Chapter 2
Complexity: Easy

63. Organic molecules are compounds that contain __________ as the primary structural atom.

Answer: carbon
Subject: Biochemistry, Chapter 2
Complexity: Moderate

64. __________ control the rate of chemical reactions that occur in the human body.

Answer: Enzymes
Subject: Enzymes, Chapter 2
Complexity: Moderate

65. A molecule of __________ contains a five-carbon sugar called deoxyribose.

Answer: DNA
Subject: Characteristics of DNA and RNA, Chapter 2
Complexity: Moderate

66. __________ are heterogeneous mixtures that have large, visible solutes.

Answer: Suspensions
Subject: Suspensions, Chapter 2
Complexity: Easy

67. The interaction of sodium and chlorine involves sodium donating one __________ to chlorine.

Answer: electron
Subject: Ionic Bonds, Chapter 2
Complexity: Moderate

68. An example of a(n) __________ bond is when two hydrogen atoms bond to form a hydrogen molecule.

Answer: covalent
Subject: Covalent Bonds, Chapter 2
Complexity: Moderate

69. Most atoms that have only one or two __________ shell electrons are electropositive.

Answer: valence
Subject: Ionic Bonds, Chapter 2
Complexity: Difficult

True/False

70. Copper, fluorine, and iron are major elements of the human body.

Answer: False
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

71. Lipids are a poor source of stored energy.

Answer: False
Subject: Biochemistry, Chapter 2
Complexity: Easy

72. Hydrogen bonds are too weak to bind atoms together to form molecules, but are important intramolecular bonds.

Answer: True
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

73. A phospholipid consists of a glycerol portion with amino acid chains.

Answer: False
Subject: Biochemistry, Chapter 2
Complexity: Easy

74. The major function of carbohydrates in the body is to provide amino acids.

Answer: False
Subject: Biochemistry, Chapter 2
Complexity: Easy

75. Solutions are homogeneous mixtures of components that may be solids, liquids, or gases.

Answer: True
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

76. The three basic types of mixtures include colloids, compounds, and acid-bases.

Answer: False
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

77. Neutrons bear a positive electrical charge.

Answer: False
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

78. Electrons bear a negative electrical charge.

Answer: True
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

79. Acidosis is an abnormal physiological state caused by blood pH that is higher than 7.35.

Answer: False
Subject: atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

80. The simplest and smallest atom is lithium.

Answer: False
Subject: Atoms, Molecules, and Chemical Bonds, Chapter 2
Complexity: Easy

81. Synthesis is a reaction that occurs when two or more atoms bond to form a more complex product.

Answer: True
Subject: Synthesis Reactions, Chapter 2
Complexity: Easy

82. Ammonia is a waste product of the body’s breakdown of lipids.

Answer: False
Subject: Acids, Bases, and the pH Scale, Chapter 2
Complexity: Moderate

83. Hydrogen ion concentration can be measured by a value called pH.

Answer: True
Subject: Acids, Bases and the pH Scale, Chapter 2
Complexity: Moderate

84. Alkalosis results from blood pH that is lower than 7.

Answer: False
Subject: Acids, Bases and the pH Scale, Chapter 2
Complexity: Moderate

85. For many chemical reactions, water is an important reactant.

Answer: True
Subject: Water, Chapter 2
Complexity: Easy

86. A salt is an ionic compound that contains cations other than hydrogen ions.

Answer: True
Subject: Salts, Chapter 2
Complexity: Moderate

87. Saturated fats have fatty acid chains with single covalent bonds between carbon atoms.

Answer: True
Subject: Triglycerides, Chapter 2
Complexity: Moderate

88. Phospholipids are structurally related to glycolipids, and are actually modified cholesterols.

Answer: False
Subject: Phospholipids, Chapter 2
Complexity: Moderate

89. Most organic cofactors are derived from vitamin D.

Answer: False
Subject: Enzyme Characteristics, Chapter 2
Complexity: Moderate