51. The efficiency of photosynthesis is reduced
a.
by the damaging effects of excess humidity.
b.
by the damaging effects of excess intermediates in the light-dependent reactions.
c.
by the low efficiency of ATP synthase.
d.
by inhibition of rubisco by excess ATP.
e.
by a lack of ATP.
52. Typical agricultural crops store how much of their absorbed solar energy in the form of biomass?
a.
0.1% to 0.5%
b.
1% to 5%
c.
10% to 50 %
d.
100%
e.
0.01% to 0.05%
53. Where can you find ATP synthase in a plant cell?
a.
in the thylakoid membrane
b.
in the mitochondrial inner membrane
c.
embedded in the plasma membrane
d.
only in the nucleus
e.
thylakoid and inner mitochondrial membranes
54. Which products of the light reactions are used in the Calvin cycle?
a.
ADP and NADP+
b.
Water, O2, ATP.
c.
CO2 and RuBP
d.
electrons and photons
e.
ATP and NADPH
55. Rubisco has 16 subunits joined together to make a functional unit. Eight of the subunits are large, the
other 8 are small. What does this tell you about this protein’s structure?
a.
It is an example of a protein having quaternary structure.
b.
The protein has tertiary structure and domains but no quaternary structure.
c.
The primary sequence of all 16 subunits is identical, which is a unique property of
enzymes participating in photosynthesis.
d.
The subunits each have 8 alpha helices in order to bind to CO2 and RuBP.
e.
It’s an enzyme that is extremely resistant to denaturation.
56. If you put chloroplasts in the dark, they can continue to make sugar if provided with
a.
NADPH, ATP, and CO2.
b.
NADPH and ATP.
c.
CO2 and ATP.
d.
NADPH, CO2, and ADP.
e.
water and ATP.
57. Which Calvin Cycle products are used in the light reactions?
a.
G3P, ATP, and NADPH.
b.
O2, water, and ATP.
c.
ADP, Pi, and NADP+.
d.
electrons from CO2.
e.
protons and Pi.
58. What is the primary difference between NAD+ and NADP+ (shown in the figure above)?
a.
NAD+ functions as an electron transporter, whereas NADP+ does not.
b.
NAD+ functions as an electron transporter in chloroplasts while NADP+ functions as an
electron transporter in mitochondria.
c.
Both function as electron carriers, but NADP+ has a third phosphate group and NAD+ does
not.
d.
Both transport electrons to the electron transport chain (ETC) found on the inner
mitochondrial membrane, but NADP+ transfers its electrons to the ETC at a higher energy
level.
e.
NAD+ functions as a free energy source for cells while NADP+ does not.
59. C3 plants are more susceptible to photorespiration than either C4 or CAM plants, so why do most
plants lack the C4 pathway?
a.
Rubisco is more efficient in C3 plants when compared to rubisco C4 and CAM plants.
b.
Photorespiration is not a serious problem for most plants.
c.
Most plant species do not have vacuoles in their cells to store the malate generated from
CO2 taken in during the night.
d.
There is an energetic cost to C4 and CAM pathways that only makes them advantageous in
very hot and/or arid environments.
e.
Switching between C3, C4, and CAM photosynthesis is very difficult for most plants.
Use the figure above and the information below for the following question(s).
You grow 25 plants under 5 different experimental treatment conditions to determine the effects of
light and CO2 on plants. Each plant started out with the same biomass and was measured again in 10
days; the average results for each plant group are in the graph. The five conditions are as follows:
I.
Normal light, 0.5x CO2 concentration
II.
Normal light, 1x (normal) CO2 concentration
III.
Normal light, 2x CO2 concentration
IV.
No light, 1x CO2 concentration
V.
No light, 2x CO2 concentration
60. In the figure above, this group of plants was given treatment I.
a.
1
b.
2
c.
3
d.
4
e.
5
61. In the figure above, this group of plants was given treatment II.
a.
1
b.
2
c.
3
d.
4
e.
5
62. In the figure above, this group of plants was given treatment III.
a.
1
b.
2
c.
3
d.
4
e.
5
63. In the figure above, this group of plants was given treatment IV.
a.
1
b.
2
c.
3
d.
4
e.
5
64. In the figure above, this group of plants was given treatment V.
a.
1
b.
2
c.
3
d.
4
e.
5
65. Photosynthesis must provide a source of electrons and H+ ions because ______________.
a.
atmospheric CO2 must be oxidized by adding electrons
b.
CO2 must be reduced to produce sugars
c.
hydrogen atoms are added to oxygen to form water
d.
hydrogen ions and electrons react to produce hydrogen gas
e.
hydrogen ions and electrons are converted into oxygen gas
66. Which of the following substances is NOT required at some point during photosynthesis?
a.
H2O
b.
O2
c.
NADP
d.
ADP
e.
ATP
MATCHING
Match each of the following terms with its correct definition.
a.
The emission of light of a longer wavelength than the absorbed light.
b.
The generation of ATP via a proton gradient created by light-energized electrons moving
down an electron transport chain.
c.
The site of the light-independent reactions in the chloroplast.
d.
Complexes of light-absorbing molecules clustered in the thylakoid and stromal
membranes of chloroplasts.
e.
Membranous connections between granum that allow individual thylakoid lumens to form
a single, contiguous compartment.
f.
The addition of O2 to RuBP by rubisco, resulting in a net loss of carbon from the Calvin
cycle.
g.
The molecule used to store carbon overnight in CAM plants.
h.
Organisms that use CO2 as their carbon source and light as their energy source.
67. photoautotrophs
68. photosystems
69. photophosphorylation
70. stroma
71. photorespiration
72. fluorescence
73. stromal lamellae
74. malate
Classification
Use the five processes listed below for the following question(s).
a.
noncyclic electron flow
b.
cyclic electron flow
c.
carbon fixation stage of the Calvin cycle
d.
carbon reduction stage of Calvin cycle
e.
RuBP regeneration stage of Calvin cycle
75. This converts G3P into a molecule that can bind to CO2.
76. This form of the light-dependent reactions produces ATP and NADPH in equal molar ratios.
206
77. This reaction uses rubisco, the most abundant enzyme on Earth.
78. This is when the G3P product is actually synthesized in the chloroplast.
79. This allows for the production of additional ATP to drive the RuBP regeneration process.
Choice
For each of the following statements, choose the most appropriate process.
a.
light-dependent reactions only
b.
Calvin cycle only
c.
light-dependent reactions and the Calvin cycle both
d.
neither the light-dependent reactions nor the Calvin cycle
80. produces O2
81. consumes NADPH
82. creates a proton gradient
83. requires ATP
84. produces ADP
85. requires G3P to continue
86. produces ATP
87. consumes O2
88. requires water
89. produces NADP+
90. requires glucose
91. requires rubisco
92. occurs during the daytime
Labeling
Identify each part of the following illustration.
208
93. thylakoid lumen
94. outer membrane
95. stroma
96. thylakoid membrane
97. inner membrane
98. site of light-dependent reactions
99. site of light-independent reactions
100. where you would search for rubisco
101. membrane most important in generating a proton gradient for ATP synthesis
102. membrane most likely to surround an acidic solution
103. where you would find chlorophyll
104. where photorespiration occurs
105. this membrane is in contact with the cytosol
106. prevents the stroma from coming into contact with the outer membrane
107. where you would find carotenoids
SHORT ANSWER
108. Explain why we say nearly all life on Earth ultimately depends on the sun for energy.
109. Why do the photosynthetic tissues of plants look green?
110. Why is rubisco considered an important enzyme?
111. What is a major similarity and difference between photorespiration and aerobic respiration?
MODIFIED TRUE/FALSE
If the statement is true, answer “T“. If the statement is false, answer “F” and make it correct by
changing the underlined word(s) and writing the correct word(s) in the answer blank(s).
112. The process of photosynthesis, including all of the enzymes and chemical intermediates, is completely
understood.
113. Atmospheric O2 is actually a waste product of photosynthesis.
114. Glucose is the only sugar produced from photosynthesis.
115. The genes encoding for proteins involved in photosynthesis are located in the chloroplast.
116. The arrangement of photosystems I and II in the thylakoid membrane is exactly like drawn in the Z-
pathway of most textbooks.
117. Not all plants can use the C4 pathway to avoid photorespiration.
118. Glycolate is released into the atmosphere to prevent it from killing the plant.
ESSAY
119. Explain why it is important, from a global standpoint, to try to improve the efficiency of
photosynthesis in common crops. Specify which aspect(s) of photosynthesis we should target.
120. What are some of the problems that must be addressed when planting C3 plants in hot, arid climates
for ornamental purposes?
121. Compare and contrast the role of O2 and H2O in photosynthesis and cellular respiration.