Unit One: Biochemistry and Cellular transport Review
Multiple Choice : Identify the choice that best completes the statement or answers the question.
1. 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
2. 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
3. In living organisms, buffers do which of the following?
a. prevent charged particles from entering cells b. neutralize the effect of enzymes c. maintain pH in the
cells within a narrow range, allowing enzymes to function d. allow the pH of cells to change without
affecting the action of the enzymes e. maintain cytoplasm in a fluid condition
4. Which three of the following are characteristics of hydrogen bonds?
I. They are responsible for the surface tension properties of water.
II. They are responsible for the relatively high boiling point of water.
III. They are stronger than ionic bonds.
IV. They are present in all substances.
V. They are weaker than covalent bonds.
a. III, IV and V b. I, II and V c. I, III and IV d. II, III and IV e. I, III, and IV
5. 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 b. both ionic and covalent c. a hydrogen bond d. a covalent bond e. a strong ionic
bond
6. Choose the element that is found in all organic compounds.
a. nitrogen b. carbon c. sulphur d. hydrogen e. oxygen
7. The following structural formula is representative of which functional group?
a. sulfhydryl b. hydroxyl c. carbonyl d. carboxyl e. amino
8. What name is given to compounds in which a carbon atom only bonds to hydrogen and other carbon atoms?
a. fatty acids b. hydrocarbons c. lipids d. nucleic acids e. carbohydrates
9. The following structural formula is representative of which functional group?
a. sulfhydryl b. hydroxyl c. carboxyl d. carbonyl e. amino
10.The following structural formula is representative of which functional group?
a. sulfhydryl b. hydroxyl c. carboxyl d. carbonyl e. amino
11. An amino acid always has an amino group, as its name suggests. What other group is also present in all amino
acids?
a. a methyl group b. an aldehyde group c. a carbonyl group d. a carboxyl group e. a hydroxyl group
12. Structurally, a sulfhydryl group is most similar to which of the following?
a. carbonyl b. carboxyl c. acetyl d. hydroxyl e. amino
13. A nitrogen atom would be found bonded to a hydrogen atom in which of the following functional groups?
a. sulfhydryl b. hydroxyl c. carboxyl d. carbonyl e. amino
14. Which of the functional groups illustrated below would you expect to find in an amino acid?
1
2
3
4
5
a. 1, 2, and 4 b. 2, and 3 c. 2, 4, and 5 d. 1 and 4 e. 3 and 5
15. In terms of maintaining the shape of an enzyme, the strongest bonds involved are
a. covalent (disulfide) bonds b. dipole-dipole interactions c. ionic interactions d. hydrogen bonds
e. hydrophobic bonds
16. Which of the following functional groups would be found in a monosaccharide?
a. carbonyl and hydroxyl b. glycosidic and hydroxyl c. carboxyl an amino d. carboxyl and carbonyl
e. hydroxyl and sulfhydryl
17. Of the following, which is not considered to by a polymer?
a. cellulose b. RNA c. starch d. protein e. fat
18. Of the following biological compounds, which one contains the element, nitrogen?
a. fatty acids b. sugar c. glycerol d. starch e. protein
19. When digested, which of the following substances would yield a mixture of amino acids?
a. carbohydrate b. nucleic acids c. sugar d. protein e. fat
20. From the following list, which is an example of a monosaccharide?
a. maltose b. glycogen c. cellulose d. glucose e. sucrose
21. 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 b. amino acids c. enzymes d. proteins e. peptides
22. In humans, the function of glycogen is to
a. synthesize proteins b. dilute the blood plasma c. keep glucose available d. increase osmotic pressure in
cells e. store glucose in plants
23. When a molecule of glycerol reacts with one or more fatty acids an ester linkage results. The formation of this
linkage is a result of a reaction between
a. an amino acid and a carboxylic acid b. two alcohols c. an alcohol and a carboxylic acid d. two
carboxylic acids e. two amino acids
24. 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) b. hydrogenation c. hydrolysis d. oxidation e. reduction
25. The hydrolysis (breakdown) of an ester results in
a. a sugar and an acid b. two acids c. an acid and an amine d. two sugars e. an acid and an alcohol
26. The hydrolysis (breakdown) of a dipeptide results in the production of which of the following?
a. a sugar and an amino acid b. two amino acids c. an acid and an amine d. two sugars e. an amino acid
and an alcohol
27. When starch is broken down during digestion, which of the following is the product?
a. cellulose b. lactose c. mannose d. maltose e. sucrose
28. The production, or synthesis, of proteins, fats, and carbohydrates involves the
a. production of ATP b. addition of water c. removal of water d. temporary hydrogen bonding e. removal
of nitrogen
29. What fatty acids and glycerol chemically combine to form a fat, one other product is
a. carbon dioxide b. ATP c. a monosaccharide d. water e. an amino group
30. 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
31. 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 b. carbohydrates c. proteins d. vitamins e. lipids
32. Energy released during cellular respiration is stored in a compound called
a. glucose. b. ADP. c. ATP. d. DNA. e. RNA.
33. An animal cell is capable of all of the following, except
a. respiration. b. reproduction. c. maintaining turgor pressure. d. growth. e. metabolism.
34. In which type of cell would you find the fewest mitochondria?
a. muscle b. nerve c. digestive d. adipose e. all cells have the same number of mitochondria
35. At what organelle are amino acids bonded together?
a. endoplasmic reticulum b. nucleus c. vacuole d. ribosome e. amino acids are not bonded at an organelle
36. Ribosomes are composed of
a. DNA and RNA. b. rRNA and proteins. c. DNA and proteins. d. proteins and lipids. e. ribosomes are
organelles and are not composed of anything.
37. Cells specialized to secrete protein usually have large numbers of
a. rough endoplasmic reticulum. b. Golgi apparatus. c. smooth endoplasmic reticulum. d. lysosomes.
e. vacuoles.
38. The organelle responsible for storage and packaging of proteins is the
a. nucleus. b. ribosome. c. endoplasmic reticulum. d. vesicle. e. Golgi apparatus.
39. Small protein-filled sacs in animal cells are known as
a. vacuoles. b. droplets. c. vesicles. d. ribosomes. e. microtubules.
40. The process by which vesicle contents are released from a cell is
a. diffusion. b. osmosis. c. endocytosis. d. exocytosis. e. respiration.
41. The main function of vesicles within the cell is
a. maintaining turgor. b. endocytosis. c. protein synthesis. d. transport. e. none of the above.
42. Vesicles are formed during
a. protein synthesis. b. endocytosis. c. cellular respiration. d. photosynthesis. e. cell division.
43. Lysosomes are formed by the
a. Golgi apparatus. b. nucleus. c. mitochondria. d. ribosomes. e. vacuoles.
44. Lysosomes contain
a. enzymes. b. lipids. c. nucleic acids. d. carbohydrates. e. all of the above.
45. Most body cells are continually being replaced as they wear out. The organelle responsible for breaking down
worn-out cells is the
a. cell membrane. b. vacuole. c. vesicle. d. endoplasmic reticulum. e. lysosome.
46. Microfilaments
a. provide shape and movement for cells. b. transport materials throughout the cytoplasm. c. convert
chemical energy to electrical energy. d. are artificial structures produced using nanotechnology. e. none of
the above.
47. The pressure exerted against the cell membrane and cell wall is known as
a. wall pressure. b. turgor pressure. c. negative pressure. d. cell pressure. e. none of the above.
48. A plant vacuole serves as a storage space for
a. water. b. sugars. c. minerals. d. proteins. e. all of the above.
49. Animal cells are not able to produce sugars because they lack
a. Golgi apparatus. b. mitochondria. c. chloroplasts. d. amyloplasts. e. chromoplasts.
50. Which of the following is not necessary for a plant to perform photosynthesis?
a. carbon dioxide b. water c. sunlight d. minerals e. sugar
51. Plant cell walls are primarily composed of
a. starch. b. pectin. c. protein. d. cellulose. e. chlorophyll.
52. Which of the following are functions of cell walls?
a. protect the cell b. support the cell c. regulate passage of materials d. all of the above e. only a and b
53. A mammal's cells require more mitochondria than a lizard's because
a. mammals eat more. b. mammal cells are not as efficient. c. mammal foods are harder to digest.
d. mammals use energy to maintain body temperature. e. mammal cell do not require more mitochondria.
54. Which of the following statements is not a part of the cell theory?
a. New cells arise from cells that already exist. b. All cells contain a true nucleus. c. All living things are
composed of one or more cells. d. The cell is the smallest entity that retains the properties of life.
55. Choose the best description of the nucleus.
a. storage centre b. control centre c. energy centre d. excretion centre e. transport centre
56. Which of the following compounds is a component of cell membranes?
a. nucleic acids b. cellulose c. proteins d. water
57. Which of these cells would not be classified as eukaryotic?
a. plant cells b. fungi cells c. blue-green algae cells d. animal cells
58. The cell membrane is best described as
a. impermeable. b. selectively permeable. c. permeable. d. opaque.
59. The cytoplasm is the site of
a. chemical reactions. b. nutrient processing. c. storage of wastes. d. transport of nutrients. e. all of the
above.
60. The organelle responsible for ribosome formation is the
a. Golgi apparatus. b. endoplasmic reticulum. c. nucleus. d. nucleolus. e. vesicle.
Matching
Match each item with the correct statement below.
a. London dispersion
b. polar covalent bonds and symmetrical structure
c. intermolecular
d. hydrophobic
e. van der Waals forces
f. hydrogen bond
g. polar covalent bonds and asymmetrical structure
h. intramolecular
i. hydrophilic
j. dipole-dipole
____
____
____
____
____
____
____
____
61.
62.
63.
64.
65.
66.
67.
68.
What makes water a highly polar molecule?
What are bonds between molecules called?
What is the only force of attraction between noble gases?
What force is responsible for holding polar molecules to one another?
What dipole-dipole force results between H and either N, O or F?
What is the collective name for intermolecular bonding?
What is a property of nonpolar molecules?
What is a property of polar molecules?
Match each item with the correct statement below.
a. strand
g.
b. ribose
h.
c. adenosine triphosphate (ATP)
i.
d. adenine
j.
e. guanine
k.
f. cytosine
l.
thymine
uracil
antiparallel
parallel
guanosine triphosphate (GTP)
deoxyribose
____ 69. What nucleotide pairs with adenine?
____ 70. What is a series of nucleotides forming a polymer called?
____ 71. What nucleotide pairs with cytosine?
____ 72. In which direction do DNA polymers run?
____ 73. What is the name of the sugar found in DNA?
____ 74. Which is a nucleotide also important in energy-requiring reactions?
Match each item with the correct statement below.
a. pleated sheet
f.
b. phosphate group
g.
c. carbohydrates
h.
d. lipids
i.
e. essential amino acids
j.
____
____
____
____
____
____
____
____
75.
76.
77.
78.
79.
80.
81.
82.
Part of the sides of the DNA ladder.
Results in the formation of water.
Class of compounds has the most energy per gram.
An example of a secondary structure.
Humans need to have 8 or these in their diet.
Describes the breakdown of macromolecules.
Class of compounds is principally used for energy.
Forms strong tertiary structures.
Match each item with the correct statement below.
a. G
g.
b. substrate
h.
c. active site
i.
d. induced-fit
j.
e. lock and key
k.
f. organelles
l.
____
____
____
____
____
____
____
____
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
enzymes
cytoplasm
enzyme-substrate complex
minerals
cofactors
coenzymes
Decreases the energy of activation.
Unaffected by an enzyme.
Enzyme changes shape to better accommodate the substrate.
An enzyme with its substrate attached to the active site.
The location where substrate binds to an enzyme.
Organic nonprotein components that are needed for some enzymes to function.
Nonprotein components that are needed for some enzymes to function.
The reactant that an enzyme acts on when it catalyzes a chemical reaction.
Match each item with the correct statement below.
a. competitive inhibitor
e.
b. noncompetitive inhibitor
f.
c. substrate
g.
d. allosteric site
h.
____
____
____
____
____
____
____
condensation reaction
hydrolysis reaction
hydrogen bonds
catabolic reaction
disulfide bridges
activator
allosteric inhibitor
feedback inhibition
active site
The location where the substrate binds to an enzyme.
A substance that competes with the substrate for the active site.
Method of metabolic control.
Effects of this substance cannot be affected by increasing substrate.
Binds to allosteric site and stabilizes inactive form of the enzyme.
The reactant that an enzyme acts on when it catalyzes a chemical reaction.
Binds to allosteric site and keeps all active sites available.
____ 98. Nonactive site that can bind substances to speed/slow a reaction.
Match the terms used in the study of cell structure with the appropriate definition.
a. cell membrane
e. nucleolus
b. eukaryotic
f. cytoplasm
c. prokaryotic
g. flagella
d. chromosomes
h. cilia
____
____
____
____
____
____
____
____
99.
100.
101.
102.
103.
104.
105.
106.
having a true membrane-bounded nucleus
may be involved in the production of RNA
create currents to move materials past cell
the fluid and other materials between the plasma membrane and the nucleus
protein and lipid structure that regulates movement of materials into and out of the cell
chromosomes not surrounded by a nuclear membrane
use contractile proteins to help cell locomotion; usually single or in pairs
threadlike structures made of DNA
Match the organelle with it's function.
a. nuclear envelope
b. ribosomes
c. vesicle
d. mitochondrion
____
____
____
____
____
____
____
____
107.
108.
109.
110.
111.
112.
113.
114.
e.
f.
g.
h.
microfilaments
microtubules
cell membrane
smooth endoplasmic reticulum
protein-filled sac
regulates the entry and exit of materials in and out of the cell
provide shape and movement for cells
regulates passage of materials into and out of the nucleus
transport materials throughout cytoplasm
synthesis of lipids and transport of these throughout cell
cellular respiration
synthesize proteins
Match the organelle with the chemical process associated with it.
a. rough endoplasmic reticulum
e. smooth endoplasmic reticulum
b. mitochondrion
f. ribosome
c. Golgi apparatus
g. nucleolus
d. chloroplast
h. nucleus
____
____
____
____
____
____
____
____
115.
116.
117.
118.
119.
120.
121.
122.
photosynthesis
polymerize proteins from amino acids
transport of secretory proteins
store, modify, and package proteins
RNA synthesis
DNA replication
cellular respiration
lipid synthesis and transport
Match the cellular structures with the membrane-related statement that best applies.
a. nucleus
e. mitochondrion
b. endoplasmic reticulum
f. nucleolus
c. chloroplast
d. cytoplasm
____
____
____
____
____
____
____
123.
124.
125.
126.
127.
128.
129.
g. Golgi apparatus
formed by parallel membranes
not surrounded by a membrane
surrounded by a semipermeable membrane
formed by membranous sacs piled on top of each other
smooth outer membrane and inner membrane with projections called cristae
surrounded by a double membrane with pores
inner structures organized into stacks of grana
Short Answer
130. Explain the following terms and give an example of each.
a. hydrogen bond
b. covalent bond
131. Explain the significance of electronegativity. Using an O-H bond as an example, classify this bond as to its
type and explain why it is classified this way.
132. Construct a table to summarize the four major types of biochemical reactions studied in this course. For each
type give the name, a word summary of what happens during the reaction, and an example of where the
reaction might be biologically important.
133. Explain how an enzyme is able to catalyze the synthesis of a large molecule from two smaller molecules.
uni
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
D
B
C
B
D
B
D
B
E
D
D
D
E
D
A
A
E
E
D
D
A
C
C
A
E
B
D
C
D
D
C
C
C
D
D
B
A
E
C
D
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
D
B
A
A
E
A
B
E
C
E
D
E
D
B
B
C
C
B
E
D
MATCHING
61.
62.
63.
64.
65.
66.
67.
68.
G
C
A
J
F
E
D
I
69.
70.
71.
72.
73.
74.
G
A
E
I
L
C
75.
76.
77.
78.
79.
80.
81.
82.
B
F
D
A
E
I
C
J
83.
84.
85.
86.
87.
88.
89.
90.
G
A
D
I
C
L
K
B
91.
92.
93.
94.
95.
96.
97.
98.
H
A
G
B
F
C
E
D
99.
100.
101.
102.
103.
104.
105.
106.
B
E
H
F
A
C
G
D
107.
108.
109.
110.
111.
112.
113.
114.
C
G
E
A
F
H
D
B
115.
116.
117.
118.
119.
120.
121.
122.
D
F
A
C
G
H
B
E
123. B
124.
125.
126.
127.
128.
129.
F
D
G
E
A
C
SHORT ANSWER
130. a. A hydrogen bond is a weak, intermolecular attractive force between an electropositive hydrogen of one
polar molecule and an electronegative N, O, or F or a neighbouring polar molecule. Water molecules are
attracted to one another by hydrogen bonds.
b. A covalent bond is a relatively strong bond in which a pair of electrons is shared by two atoms, resulting
in the filling of the outer electron energy levels of both atoms at the same time. Carbon is an important
biological element that forms covalent bonds.
131. - 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.
- The
of oxygen, 'O', is 3.5 that of hydrogen, 'H', is 2.1. The difference between these two values is 1.4.
which is an indication that the bond is polar covalent due to the uneven sharing of electrons between the
oxygen and hydrogen.
132.
Name Of Reaction
Summary Of Changes
Example
dehydration synthesis
(condensation)
two molecules joined; water
removed from the point where
the molecule join
synthesis of macromolecules
for storage of energy or
information
hydrolysis
large molecule split into two
smaller ones; water added at the
point where the molecules split
digestion: breakdown to
smaller molecules of fewer
kinds for active transport
redox
hydrogen atoms or electrons
transferred between reactants
energy storage and transfer in
cells
acid + base – > water and salt
stomach acid neutralized by
bile and sodium bicarbonate
in pancreatic juice in the
duodenum
neutralization
133. - Enzymes are protein molecules with a specific three-dimensional shape with an active site that can match
up with the specific shape of a substrate molecule and bind onto them by hydrogen bonds, forming an
enzyme-substrate complex.
- When the shape of the substrate is distorted by the enzyme, it lowers the activation energy, allowing them
to bond together to make a large molecule that can then be released by the enzyme.