Photosynthesis Flashcards
1
Q
the process that converts solar energy into chemical energy
A
photosynthesis
2
Q
nourishes almost the entire living world directly or indirectly
A
photosynthesis
3
Q
sustain themselves without eating anything derived from other organisms
A
autotrophs
4
Q
producers of the biosphere
A
autotrophs
5
Q
produces organic molecules from CO2 and other inorganic molecules
A
autotrophs
6
Q
almost all plants are ?
A
photoautotrophs
7
Q
uses the energy of sunlight to make organic molecules from H2O and CO2
A
photoautotrophs
8
Q
occurs in plants, algae, certain other protists, and some prokaryotes
A
photosynthesis
9
Q
give examples of photoautotrophs
A
plants
multicellular alga
unicellular protist
cyanobacteria
purple sulfur bacteria
10
Q
obtain their organic material from other organisms
A
heterotrophs
11
Q
consumers of the biosphere
A
heterotrophs
12
Q
depend on photoautotrophs for food and O2
A
heterotrophs
13
Q
structurally similar to and likely evolved from photosynthetic bacteria
A
chloroplast
14
Q
site of photosynthesis in plants
A
chloroplast
15
Q
green color is from ?
A
chlorophyll
16
Q
the green pigment within chloroplasts
A
chlorophyll
17
Q
drives the synthesis of organic molecules in the chloroplast
A
light energy absorbed by chlorophyll
18
Q
CO2 enters and O2 exits the leaf through microscopic pores called ?
A
stomata
19
Q
chloroplasts are found mainly in cells of the
A
mesophyll
20
Q
the interior tissue of the leaf
A
mesophyll
21
Q
typical mesophyll cell has ? chloroplasts
A
30-40
22
Q
chlorophyll is in the membranes of ?
A
thylakoids
23
Q
connected sacs in the chloroplast
A
thylakoids
24
Q
may be stacked in columns called grana
A
thylakoids
25
TRUE OR FALSE
chloroplasts also contain stroma
true
26
TRUE OR FALSE
stroma is a dense fluid
true
27
photosynthesis equation
6 CO2 + 12 H2O + Light energy -> C6H12O6 + 6 O2 + 6 H2O
28
splits H2O into hydrogen and oxygen and incorporating the electrons of hydrogen into sugar molecules
chloroplasts
29
TRACKING ATOMS THRU PHOTOSYNTHESIS
reactants
6 CO2, 12 H2O
30
TRACKING ATOMS THRU PHOTOSYNTHESIS
products
C6H12O6, 6 H2O, 6 O2
31
is a redox process in which H2O is oxidized and CO2 is reduced
photosynthesis
32
H2O is ?
a. oxidized
b. reduced
a. oxidized
33
CO2 is ?
a. oxidized
b. reduced
b. reduced
34
photosynthesis consists of ?
light reactions and Calvin cycle
35
light reactions is also called as the ?
photo part
36
Calvin cycle is also called as the ?
synthesis part
37
the light reaction "basic" steps (4 sha)
split H2O
release O2
reduce NADP+ to NADPH
generate ATP from ADP by photophosphorylation
38
the Calvin cycle (in the stroma) forms
sugar from CO2 with the use of ATP and NADPH
39
the Calvin cycle begins with ? which ?
carbon fixation; incorporates CO2 into organic molecules
40
solar-powered chemical factories
chloroplasts
41
thylakoids transform ? into ?
light energy into the chemical energy of ATP and NADPH
42
form of electromagnetic energy
light
43
electromagnetic energy is also called
electromagnetic radiation
44
TRUE OR FALSE
light travels in rhythmic waves
true
45
the distance between crests of waves
wavelength
46
determines the type of electromagnetic energy
wavelength
47
the entire range of electromagnetic energy, or radiation
electromagnetic spectrum
48
consists of wavelengths that produce colors we can see
visible light
49
light consists of discrete particles called
photons
50
substances that absorb visible light
pigments
51
TRUE OR FALSE
different pigments absorb different wavelengths
true
52
wavelengths that are not absorbed
reflected or transmitted
53
leaves appear green because ?
chlorophyll reflects and transmits green light
54
measures a pigment’s ability to absorb various wavelengths
spectrophotometer
55
sends light through pigments and measures the fraction of light transmitted at each wavelength
spectrophotometer
56
a graph plotting a pigment’s light absorption versus wavelength
absorption spectrum
57
absorption spectrum of chlorophyll a
violet-blue and red light (work best for photosynthesis)
58
profiles the relative effectiveness of different wavelengths of radiation in driving a process
action spectrum
59
action spectrum of photosynthesis was first demonstrated in ? by ?
1883 by Theodor W. Engelmann
60
areas receiving wavelengths favorable to photosynthesis produced ?
excess O2
61
main photosynthetic pigment
chlorophyll a
62
broaden the spectrum used for photosynthesis
accessory pigments / chlorophyll b
63
absorb excessive light that would damage chlorophyll
carotenoids
64
COMPLETE
principal -> ? -> ?
chlorophyll a -> bacteriochlorophyll
65
COMPLETE
accessory -> ??? -> ?? -> ??
chlorophyll b, c, d, carotenoids, phycobilins
carotenoids -> carotene -> xanthophyll
phycobilins -> phycoerythrin -> phycocyanin
66
chlorophyll a is for
green plants and cyanobacteria
67
chlorophyll b is for
green algae and all higher plants
68
chlorophyll c is for
dinoflagellates, diatoms, and brown algae
69
chlorophyll d is for
red algae
70
chlorophyll e is for
xathophycean algae
71
types of chlorophyll
chlorophyll a-e
bacteriochlorophyll a-b
chlorobium chlorophyll 650 & 666
72
carotene is for
lycopene (red)
73
xanthophyll has what color and what is it for
yellow color; violaxanthin, fucoxanthin (brown algae), and lutein
74
types of carotenoids
carotene & xanthophyll
75
types of phycobilins
phycocyanin & phycoerythrin
76
phycocyanin is for
cyanobacteria
77
phycoerythrin is for
red algae
78
Chlorophyll 'b' differs from Chlorophyll 'a' by
CHO (aldehyde) group instead of CH3 (Methyl)
79
Chlorophyll 'c' differs from Chlorophyll 'a' by
lacking phytol tail
80
Chlorophyll 'd' differs from Chlorophyll 'a' by
having O-CHO group instead of CH-CH2 group
81
Pheophytin resembles Chlorophyll 'a' except
it lacks Mg atom and has two H atoms
82
COMPLETE THE SENTENCE
Phycobilins have ? and they have neither ?.
open tetra pyrrols; Mg nor phytol chain
83
yellow to orange pigments, absorbs light strongly in the blue to violet region of visible spectrum
carotenoids
84
protect chlorophyll from photo-oxidative damage; also called as shield pigments
carotenoids
85
pigments absorb light and transfer these to chlorophyll
carotenoids
86
Ripening of fruits, floral colours and leaf colour change during autumn is due to
carotenoids
87
orange, red, yellow, and brownish pigments, hydrocarbons (lipids)
carotenes
88
the most abundant in plants and it is a precursor of Vitamin A
carotenes
89
the red pigment found in the fruits of tomato, red peppers and roses
carotenes
90
yellow pigments are like carotenes but contain oxygen
xanthophylls
91
is responsible for yellow colour change of leaves during autumn season
xanthophylls - lutein
92
examples of xanthophylls
lutein, violaxanthin, and fucoxanthin
93
proteinaceous pigments
phycobilins
94
soluble in water, and do not contain Mg and Phytol tail
phycobilins
95
light-absorbing “head” of molecule
porphyrin ring
96
interacts with hydrophobic regions of proteins inside thylakoid membranes of chloroplasts
hydrocarbon tail
97
when a pigment absorbs light, it goes from a ground state to an ? which is ?
excited state which is stable
98
When excited electrons fall back to the ground state —
photons are given off
99
afterglow
fluorescence
100
reaction-center complex associated with light-harvesting complexes
photosystem
101
funnel the energy of photons to the reaction center
light-harvesting complex
102
pigment molecules bound to proteins
light-harvesting complex
103
accepts an excited electron from chlorophyll a
primary electron acceptor
104
two types of photosystems in the thylakoid membrane
photosystem i and photosystem ii
105
functions first and is best at absorbing a wavelength of 680 nm
photosystem ii
106
reaction-center chlorophyll a of PS II
P680
107
best at absorbing a wavelength of 700 nm
photosystem i
108
reaction-center chlorophyll a of PS I
P700
109
two possible routes for electron flow
cyclic & linear
110
the primary pathway, involves both photosystems and produces ATP and NADPH using light energy
linear electron flow
111
a very strong oxidizing agent
P680+
112
uses only photosystem I and produces ATP, but not NADPH
cyclic electron flow
113
generates surplus ATP, satisfying the higher demand in the Calvin cycle
cyclic electron flow
114
Some organisms such as ? have PS I but not PS II
purple sulfur bacteria
115
thought to have evolved before linear electron flow
cyclic electron flow
116
may protect cells from light-induced damage
cyclic electron flow
117
generate ATP by chemiosmosis but use different sources of energy
chloroplasts and mitochondria
118
transfer chemical energy from food to ATP
mitochondria
119
transform light energy into the chemical energy of ATP
chloroplast
120
protons are pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the mitochondrial matrix
mitochondria
121
protons are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the stroma
chloroplast
122
produced on the side facing the stroma, where the Calvin cycle takes place
ATP and NADPH
123
regenerates its starting material after molecules enter and leave the cycle
Calvin cycle
124
the cycle builds sugar from smaller molecules by using ATP and the reducing power of electrons carried by NADPH
Calvin cycle
125
Carbon enters the cycle as CO2 and leaves as a sugar named ?
glyceraldehyde-3-phosphate (G3P)
126
For net synthesis of 1 G3P, the cycle must take place ? times, fixing 3 molecules of CO2
THREE times
127
three phases of Calvin cycle
Carbon fixation
Reduction
Regeneration
128
a molecule combines with a five-carbon acceptor molecule, namely
carbon fixation; ribulose-1,5-bisphosphate (RuBP)
129
this step makes a six-carbon compound that splits into two molecules of a three-carbon compound, namely
carbon fixation; 3-phosphoglyceric acid (3-PGA)
130
This reaction is catalyzed by the enzyme ?
RuBP carboxylase/oxygenase / rubisco
131
ATP and NADPH are used to convert the 3-PGA molecules into molecules of a three-carbon sugar, namely
reduction; glyceraldehyde-3-phosphate (G3P)
132
this stage gets its name because NADPH donates electrons to, or reduces, a three-carbon intermediate to make G3P
reduction
133
some G3P molecules go to make glucose, while others must be recycled to regenerate the RuBP acceptor.
regeneration
134
requires ATP and involves a
complex network of reactions
regeneration
135
in order for one G3P to exit the cycle (and go towards glucose synthesis), ??? must enter the cycle
three CO2 molecules
136
when CO2 molecules enter the cycle, ??? are made.
six G3P molecules
137
One exits the cycle and is used to make glucose, while the other ? must be recycled to regenerate ? molecules of the RuBP acceptor
five; three
138
? turns of the Calvin cycle are needed to make one G3P molecule that can exit
the cycle and go towards making glucose
three
139
in three turns of the Calvin cycle, 3 CO2 combine with 3 RuBP acceptors, making
-> 6 molecules of glyceraldehyde-3-phosphate (G3P)
-> 1 G3P molecule exits the cycle and goes towards making glucose.
-> 5 G3P molecules are recycled, regenerating 3 RuBP acceptor molecules.
140
in three turns of the Calvin cycle (ATP)
9 ATP are converted to 9 ADP (6 during the fixation step, 3 during the regeneration step)
141
in three turns of the Calvin cycle (NADPH)
6 NADPH are converted to 6 NADP+ (during the reduction step)
142
a G3P molecule contains three fixed carbon atoms, so it takes ? G3Ps to build a ?
2; six-carbon glucose molecule
143
It would take ? turns of the cycle, or ? CO2, ? ATP, and 12 NADPH, to produce one molecule of glucose
6; 6; 18; 12
144
a problem for plants, sometimes requiring trade-offs with other metabolic processes, especially photosynthesis
dehydration
145
on hot, dry days, plants ? stomata, which conserves ? but also limits photosynthesis
close; H2O
146
the closing of stomata reduces ? and causes O2 to build up
access to CO2
147
wasteful process
photorespiration
148
in most plants (? plants), initial fixation of CO2, via rubisco, forms a ?-carbon compound
C3; three
149
rubisco adds O2 instead of CO2 in the Calvin cycle
photorespiration
150
consumes O2 and organic fuel and releases CO2 without producing ATP or sugar
photorespiration
151
may be an evolutionary relic because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2
photorespiration
152
limits damaging products of light reactions that build up in the absence of the Calvin cycle
photorespiration
153
a problem because on a hot, dry day it can drain as much as ? of the carbon fixed by the Calvin cycle
photorespiration; 50%
154
minimizes the cost of photorespiration by incorporating CO2 into ?
C4 plants; four-carbon compounds in mesophyll cells
155
has a higher affinity for CO2 than rubisco does
PEP carboxylase
156
it can fix CO2 even when CO2 concentrations are low
PEP carboxylase
157
these four-carbon compounds are exported to ?, where they release CO2 that is then used in the Calvin cycle
bundle-sheath cells
158
some plants, including succulents, use ? to fix carbon
crassulacean acid metabolism (CAM)
159
open their stomata at night, incorporating CO2 into organic acids
CAM plants
160
TRUE OR FALSE
Stomata close during the day, and CO2 is released from organic acids and used in the Calvin cycle.
true
161
photosynthesis produces the ? in our atmosphere
O2
162
sugar made in the chloroplasts supplies ? to synthesize the organic molecules of cells
chemical energy and carbon skeletons
163
plants store excess sugar as starch in structures such as ?
roots, tubers, seeds, and fruits
