Download CHAPTER 1 SAMPLE TEST

CHAPTER 1 SAMPLE TEST
Modified True/False
Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the
sentence or statement true.
____
1. Atoms of the same element with the same number of protons, but a different number of neutrons are called
isomers. _________________________
____
2. Neutrons are so light that their mass is usually considered to be zero
____
3. The electrons in the outermost s and p orbitals are called valence orbitals. _________________________
____
4. Electronegativity is a measure of an atom's ability to attract a shared electron pair when it is participating in
a covalent bond with another atom. _________________________
____
5. Acids release hydroxyl ions into solution when they dissociate in water
____
6. The sulfhydryl group is a functional group found in some amino acids. _________________________
____
7. Radioisotopes are used to date prehistoric life forms
____
8. The amount of adenine equals the amount of cytosine in a molecule in DNA
____
9. A molecular formula gives information about the arrangement of atoms in a molecule
____ 10. Fibrous proteins are rich in  helix
____ 11. The production of a large molecule from smaller subunits is referred to as a catabolic reaction.
_________________________
____ 12. The pH of vinegar is lower than the pH of pure water
____ 13. Compounds that contain amino groups are called organic acids
____ 14. A pH of 13 would indicate acidic conditions.
____ 15. An enzyme is observed to have several -pleated sheets. These are example of tertiary structures.
_________________________
____ 16. Organisms form various types of small organic molecules called monomers, which may be linked together to
form polymers
____ 17. Chaperone proteins help assemble DNA molecules
____ 18. Several polypeptides may make a protein.
____ 19. An exothermic reaction that involves an increase in entropy is spontaneous at all temperatures.
_________________________
____ 20. An atom that has gained or lost electons is called an isotope
____ 21. The bond that results from the reaction between potassium and chlorine is an ionic bond
____ 22. Feedback inhibition is a method used by cells to control metabolic pathways in which a product formed later
in the sequence of reaction steps competitively inhibits an enzyme that catalyzes a reaction occurring earlier in
the process. _________________________
____ 23. A pentose is a monosaccharide that has four carbon atoms
____ 24. Competitive inhibitors attach to the active site of an enzyme
____ 25. The innermost energy level of an atom can accommodate only two electrons
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 26. The most abundant class of biological molecules in a “typical” cell is
a. carbohydrates
d. proteins
b. lipids
e. ammonia
c. nucleic acids
____ 27. In looking at the periodic table, the following information would be found about nitrogen:
____ 28.
____ 29.
____ 30.
____ 31.
____ 32.
____ 33.
From the above, it can be determined that an atom of nitrogen has the following characteristics:
a. it has 7 protons, 14 neutrons and 7 electrons
b. it has 2 protons in the first energy level and 5 protons in the second energy level
c. it has an atomic mass of 14 atomic mass units and 7 electrons
d. it has 7 neutrons and 4 electrons
e. it as an atomic number of 14 and contains 7 protons
Element 'X' has 7 electrons in the outermost energy level of each of its atoms. Atoms of element 'Y' also
contain 7 electrons in the outermost energy level. However, when neutral, element 'Y' has a much lower
atomic mass. Therefore
a. both elements will form covalent bonds more readily that ionic bonds
b. element 'X' has a lower electronegativity than element 'Y'
c. it is highly probable that these elements will form polar covalent bonds
d. both elements will tend to give up an electron to become chemically stable
e. there is not enough information to answer this question
Which of the following is not a type of intermolecular force of attraction?
a. covalent bond
d. hydrogen bond
b. London dispersion force
e. hydrophobic interaction
c. dipole-dipole interaction
Which of the following is the essential characteristic of a polar molecule?
a. contains double or triple bonds
b. is formed at extremely low temperatures
c. contains ions as part of the structure
d. has an asymmetrical distribution of electrical charge
e. contains the element oxygen
Isomers are molecules that
a. react readily with one another
b. have the same molecular formula
c. have different molecular masses
d. differ in the number of unsaturated bonds
e. must contain the same functional group
Starch, cellulose, and glycogen are all classified as:
a. carbohydrates
d. proteins
b. lipids
e. ammonia
c. nucleic acids
By what factor would the concentration of hydrogen (hydronium) ions be decreased if the pH of a solution
changed from 4.5 to 6.5?
____ 34.
____ 35.
____ 36.
____ 37.
____ 38.
____ 39.
____ 40.
____ 41.
a. 2
d. 20
b. 5
e. 100
c. 10
Which one of the four major lipids consists of four joined carbon rings plus various side goups?
a. fatty acids
d. steriods
b. triglycerides
e. ammonia
c. phospholipids
When atoms from two different elements are brought together under conditions that will favour a reaction and
they have similar electronegativities, which type of chemical bond is most likely to form?
a. nonpolar covalent bond
d. polar covalent bond
b. ionic bond
e. London forces
c. hydrogen bond
A chemical bond involving carbon and hydrogen (C-H) is present in many biological molecules. Based upon
their electronegativities the bond could be described as
a. a weak ionic bond
d. a covalent bond
b. both ionic and covalent
e. a strong ionic bond
c. a hydrogen bond
Choose the element that is found in all organic compounds.
a. nitrogen
d. hydrogen
b. carbon
e. oxygen
c. sulphur
Glycogen is an example of
a. carbohydrate
d. protein
b. lipid
e. ammonia
c. nucleic acid
A combination of two or more atoms of different elements in specific proportions and with a specific pattern
of bonds is known as a:
a. molecule
d. salt
b. substance
e. compound
c. isomer
A dissaccharide is formed by a condensation reaction in which two molecules are gained by the removal of a
molecule of what?
a. carbon dioxide
d. salt
b. water
e. sulfur dioxide
c. ammonia
The following structural formula is representative of which functional group?
a. sulfhydryl
d. carbonyl
b. hydroxyl
e. amino
c. carboxyl
____ 42. The following structural formula is representative of which functional group?
a. sulfhydryl
b. hydroxyl
d. carbonyl
e. amino
____ 43.
____ 44.
____ 45.
____ 46.
____ 47.
____ 48.
____ 49.
____ 50.
____ 51.
____ 52.
____ 53.
____ 54.
c. carboxyl
Which of the following is not a component of DNA?
a. deoxyribose
d. adenine
b. uracil
e. thymine
c. phosphate
A nitrogen atom would be found bonded to a hydrogen atom in which of the following functional groups?
a. sulfhydryl
d. carbonyl
b. hydroxyl
e. amino
c. carboxyl
At what pH value could an enzyme have both positive and negative charges upon it?
a. 1 and 13
d. 7
b. 1, 7, and 13
e. 1
c. 13
Of the following, which is not considered to by a polymer?
a. cellulose
d. protein
b. RNA
e. fat
c. starch
Of the following biological compounds, which one contains the element, nitrogen?
a. fatty acids
d. starch
b. sugar
e. protein
c. glycerol
There are four elements that make up all amino acids. Two of these are carbon and hydrogen. The other two
are
a. sulfur and nitrogen
d. nitrogen and oxygen
b. phosphorus and nitrogen
e. phosphorus and oxygen
c. sulfur and oxygen
When digested, which of the following substances would yield a mixture of amino acids?
a. carbohydrate
d. protein
b. nucleic acids
e. fat
c. sugar
Of the list of compounds below, which one cannot result in the production of urea, a nitrogen-containing
waste product found in urine?
a. glucose
d. proteins
b. amino acids
e. peptides
c. enzymes
When two organic molecules are joined together and a water molecule is removed, the reaction is called
which of the following?
a. dehydration synthesis (condensation)
d. oxidation
b. hydrogenation
e. reduction
c. hydrolysis
The hydrolysis (breakdown) of an ester results in
a. a sugar and an acid
d. two sugars
b. two acids
e. an acid and an alcohol
c. an acid and an amine
The hydrolysis (breakdown) of a dipeptide results in the production of which of the following?
a. a sugar and an amino acid
d. two sugars
b. two amino acids
e. an amino acid and an alcohol
c. an acid and an amine
Protons have what charge?
____ 55.
____ 56.
____ 57.
____ 58.
____ 59.
____ 60.
____ 61.
____ 62.
____ 63.
____ 64.
a. positive
d. ionic
b. negative
e. isomeric
c. neutral
The production, or synthesis, of proteins, fats, and carbohydrates involves the
a. production of ATP
d. temporary hydrogen bonding
b. addition of water
e. removal of nitrogen
c. removal of water
Which of the following properties of water helps move water to the tips of trees?
a. high specific heat of vapourization
d. high surface tension
b. adhesion
e. lower density as a solid than as a liquid
c. high solubility
Which of the following does a buffer comprise?
a. a strong acid only
d. a weak acid and a weak base
b. a weak base only
e. a weak acid and a strong base
c. a strong acid and a strong base
What fatty acids and glycerol chemically combine to form a fat, one other product is
a. carbon dioxide
d. water
b. ATP
e. an amino group
c. a monosaccharide
Which of the following bonds hold together a protein’s primary structure
a. hydrogen bonds
d. covalent bonds
b. ionic bonds
e. dipole-dipole interactions
c. London forces
The extremely large diversity of structure seen in proteins is mainly due to
a. the disulfide and hydrogen bonds that determine molecular shape
b. the action of the ribosomes
c. the precise location of specific amino acids, common to all proteins
d. different numbers, kinds, and sequences of amino acids
e. different kinds of bonds between successive amino acids
Proteins tend to denature at temperatures over
a. 0 ºC
d. 40º C
b. 10 ºC
e. 60º C
c. 20º C
Many people are aware that water is the most abundant substance in all organisms. However, next to water,
what is the major component of living cells?
a. nucleotides
d. vitamins
b. carbohydrates
e. lipids
c. proteins
The mass of an atom is determined by adding the number of
a. protons and electrons
d. isotopes
b. protons and neutrons
e. isotopes and isomers
c. neutrons and electrons
Of the following, which are reasons why molecular models are useful to biologists? Models help
I. visualize the shape of functional groups
II. visualize geometric isomers
III. visualize the three-dimensional shapes of molecules
IV. determine the presence of symmetry in molecules
V. predict products of chemical reactions
a. I only
d. III, IV and V only
____ 65.
____ 66.
____ 67.
____ 68.
____ 69.
____ 70.
____ 71.
____ 72.
____ 73.
b. I and II only
e. I, II, III, IV and V
c. I, II, IV and V only
In the electron transport chain of the mitochondria, electrons are commonly transferred from one molecule to
another. In one such reaction a Fe3+ ion in a cytochrome is converted to a Fe2+ ion. This is known as
a. isomer formation
d. hydrolysis
b. reduction
e. neutralization
c. oxidation
An oxidation/reduction is best shown by which of the following?
a. an amino and carboxyl group form a peptide bond
b. two small molecules chemically combine to form a large one
c. a base reacts with an acid to form water and a salt
d. electrons are transferred from one substance to another
e. a large molecule is broken into two smaller molecules
During photosynthesis, water molecules are split according to the following reaction:
H2O + NADP+  NADPH + H+ + O2
In the reaction, which substance undergoes reduction?
a. the hydrogen ions (protons)
d. the NADP+
b. the NADPH
e. the water molecules
c. the oxygen that is released
DNA is an example of
a. carbohydrate
d. protein
b. lipid
e. ammonia
c. nucleic acid
Of the following characteristics, which one is not true about enzymes?
a. They are essential to the metabolism of cells for the conversion of energy.
b. They function best at specific temperatures but break down at high temperatures.
c. Some enzymes need activators or cofactors.
d. They function best at a particular pH.
e. They undergo major chemical change after reacting with their specific substrate.
Of the following five statements, which is most correct with respect to enzymes?
a. A denatured enzyme is more specific in its action.
b. Denaturation of proteins always involves enzymes.
c. Catalysts prevent chemical reactions.
d. All catalysts are enzymes.
e. All enzymes are catalysts.
At which temperature would you expect any enzyme extracted from a human tissue to have its optimal
performance?
a. 5C
d. 37C
b. 10C
e. 95C
c. 25C
The activity of an enzyme can be altered by changing the pH of its surroundings slightly. This change in pH
works by
a. causing the enzyme to precipitate
b. masking its active site
c. increasing the activation energy of the reaction
d. breaking its peptide bonds
e. altering its three dimensional shape
Which of the following statements about enzymes is not true?
a. They are proteins with tertiary or quaternary structures.
b. They are very specific for the substrate to which they bind.
c. They will bind their substrate and any isomer of their substrate.
d. Their names usually end in 'ase.'
e. All of the above statements are true.
____ 74. Which of the following is a statement of the second law of thermodynamics
a. Energy is conserved in the universe
d. The entropy of the universe always
increases
b. Entropy is conserved in the universe
e. The energy of the universe always
increases
c. Living organisms are exempt from this
law
____ 75. Which of the following statements regarding enzyme inhibition is incorrect?
a. Competitive inhibitors have a similar structure to the normal substrate.
b. Competitive inhibitors bind to the active site of an enzyme.
c. Noncompetitive inhibition can be overcome by adding more substrate.
d. Noncompetitive inhibitors do not have a similar structure to the normal substrate.
e. Noncompetitive inhibitors do not bind to the active site of an enzyme.
CHAPTER 1 SAMPLE TEST
Answer Section
MODIFIED TRUE/FALSE
1.
2.
3.
4.
5.
6.
7.
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9.
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25.
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F, isotopes
F
F, valence electrons
T
F
T
T
F
F
T
F, anabolic reaction
T
F
F
F, secondary structure
T
F
T
T
F
T
F, allosterically inhibits
F
T
T
MULTIPLE CHOICE
26.
27.
28.
29.
30.
31.
32.
33.
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36.
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38.
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D
C
B
A
D
B
A
E
D
A
D
B
A
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40.
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43.
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E
B
E
D
B
E
D
E
E
D
D
A
A
E
B
A
C
B
D
D
D
D
E
C
B
E
B
D
D
C
E
E
D
E
C
D
C