DAT_Bio4_Photosynthesis Flashcards
(94 cards)
1
Q
_____ are organisms like humans that obtain chemical energy from the food they eat
A
heterotrophs
2
Q
_____ organisms are capable of making their own food
A
autotrophic
3
Q
_____ like plants capture solar energy and convert it to chemical energy by photosynthesis
A
photoautotrophs
4
Q
_____ creates chemical energy which is passed up the food web to all organisms
A
photosynthesis
5
Q
photosynthesis releases _____ which is crucial for aerobic cellular respiration
A
oxygen
6
Q
photosynthesis reduces _____ from the atmosphere
A
carbon dioxide
7
Q
photosynthesis uses _____ to make _____
A
photons light energy sugars glucose
8
Q
_____ occurs when inorganic carbon is incorporated into an organic molecule like a sugar molecule
A
carbon fixation
9
Q
write the overall chemical equation for photosynthesis
A
6CO₂ + 6H₂O -> C₆H₁₂O₆ + 6O₂
10
Q
The two stages of photosynthesis are the _________ and the ____________
A
light dependent reactions Calvin cycle
11
Q
light dependent reactions produce _____ and _____
A
ATP NADPH
12
Q
the Calvin cycle or light independent reaction uses energy stored in _____ and _____
A
ATP NADPH
13
Q
photosynthesis stores solar energy in glucose chemical bonds how do plants then use that energy
A
aerobic cellular respiration
14
Q
photosynthesis has a positive Gibbs free energy ΔG so it is _____ and _____
A
nonspontaneous endergonic
15
Q
the overall reactions of aerobic cellular respiration and photosynthesis are ______
A
opposites
16
Q
solar energy is input to photosynthesis to convert 6 _____ 6 _____ to 1 _____ and 6 _____
A
CO2 H2O Glucose O2
17
Q
chemical energy is released as heat and ATP during aerobic cellular respiration where 1 _____ and 6 _____ convert to 6 _____ 6 _____
A
glucose O2 CO2 H2O
18
Q
ATP from the light dependent reactions is not used to _____
A
power the cell
19
Q
ATP from the light dependent reactions is consumed to power the _____ which makes glucose
A
Calvin cycle
20
Q
_____ tissue is the outer layer of cells what is its function
A
epidermis; it provides protection and prevents water loss
21
Q
_____ mesophyll cells conduct most photosynthesis
A
palisade
22
Q
palisade mesophyll cells contain many _____ and are well organized as a single layer below the _____
A
chloroplasts upper epidermis
23
Q
spongy mesophyll cells conduct some photosynthesis but not as much as the _____ cells
A
palisade mesophyll
24
Q
spongy mesophyll cells have few _____
A
chloroplasts
25
spongy mesophyll cells are found toward the _____
bottom of the leaf
26
gaps between spongy mesophyll cells facilitate the movement of _____
gases
27
stomata are pores mainly found in the _____ of leaves and they are the site of _____
bottoms atmospheric gas exchange
28
_____ surround stomata and they control whether the stomata are open or closed
guard cells
29
_____ are dual membrane organelles found in plants and photosynthetic algae
chloroplasts
30
organisms with chloroplasts for photosynthesis will have _____ for cellular respiration too
mitochondria
31
chloroplasts contain thylakoids where _____ occur
light dependent reactions
32
both stages of photosynthesis occur within _____
chloroplasts
33
_____ are photosynthetic organisms that do not have a chloroplast
cyanobacteria
34
the _____ is the fluid material that fills area inside the inner membrane of a chloroplast
stroma
35
the Calvin cycle occurs in the _____ of the chloroplast
stroma
36
_____ are phospholipid bilayer structured organelles that are suspended within the stroma
thylakoids
37
Light dependent reactions occur in the _______ of chloroplasts
thylakoid membranes
38
an entire stack of thylakoids is called a _____
granum
39
a junction between two grana is called a _____
lamella
40
protons H for chloroplast chemiosmosis accumulate in the _____
thylakoid lumen
41
ATP synthesis in the chloroplast occurs as protons H flow from the _____ to the _____
thylakoid lumen stroma
42
thylakoid membranes have _____ to capture photons
photosystems
43
photosystems contain special _____ including chlorophylls and carotenoids
pigments
44
photosystem _____ are directly responsible for absorbing photons
pigments
45
what are the 2 important photosystems for photosynthesis
photosystem I and II
46
photosystems I and II each have a _____ of chlorophyll molecules located in the center of the protein This is known as the _____
special pair reaction center
47
the special pair of chlorophyll molecules in photosystem I is known as _____
P700
48
the special pair of chlorophyll molecules in photosystem II is known as _____
P680
49
_____ of water involves the splitting of H₂O molecules into electrons e protons H and oxygen gas O₂
photolysis
50
where do the electrons e from photolysis travel to in photosystem II
they travel to the special pair at P680 of photosystem II the reaction center
51
When photons reach photosystem II they will excite electrons e at the _______ This causes the electrons e to be passed to a primary __________
reaction center electron accepter
52
as electrons e travel down the primary electron transport chain ETC of the thylakoid membrane they release energy that is used for _____ into the _____ from the stroma
pumping protons H thylakoid lumen
53
after traveling down the primary electron transport chain ETC of the thylakoid membrane electrons e will reach _____
photosystem I P700 special pair reaction center
54
what is the purpose of the secondary ETC following PSI in the lightdependent reactions
to reduce NADP NADPH using NADP reductase
55
describe the general pathway of noncyclic photophosphorylation
photolysis -> Photosystem II P680 -> primary ETC -> Photosystem I P700 -> secondary ETC -> NADP + reductase to make NADPH
56
noncyclic photophosphorylation requires light photons to be absorbed _____ one time at each photosystem
twice
57
electrons e do not travel to the _____ in cyclic photophosphorylation thus _____ is not produced
second ETC NADPH
58
describe the general pathway for cyclic photophosphorylation
photolysis Photosystem II P680 primary ETC Photosystem I P700 primary ETC Photosystem I P700 etc
59
what are the products of the light dependent reactions
ATP and NADPH O₂ waste product
60
normal photosynthesis can also be called _____ because the carbon fixation step of the Calvin cycle produces threecarbon molecules
C3 photosynthesis
61
what are the products of the Calvin cycle
Glucose ADP NADP
62
the Calvin cycle is sometimes referred to as the _____ because it does not use light energy directly
light independent reactions
63
the _____ cannot occur without light because it is dependent on the high energy molecules produced from the light reaction ATP and NADPH
Calvin cycle
64
the Calvin cycle fixes _____ into _____
inorganic carbon dioxide organic glucose sugars
65
the Calvin cycle must accept _____ CO₂ molecules to synthesize _____ glucose molecule
6 CO₂ 1 C₆H₁₂O₆ glucose
66
list the 4 steps of the Calvin cycle in order
carbon fixation reduction of a 3carbon intermediate regeneration of RuBP carbohydrate synthesis
67
describe the carbon fixation step step 1 of the Calvin cycle with an equation and in words
6 CO₂ 6 RuBP 12 PGAcatalyzed by RuBisCoCO₂ onecarbon combines with RuBP fivecarbons to produce a sixcarbon molecule that splits into 2 PGA molecules threecarbons per PGA molecule
68
describe the reduction step step 2 of the Calvin cycle with an equation and in words
12 ATP 12 NADPH converts 12 PGA 12 G3PATP from the light dependent reactions will phosphorylate the PGA from carbon fixation to produce another threecarbon intermediateNADPH from the light dependent reactions reduces the threecarbon intermediate to produce G3P sugars
69
describe the regeneration step step 3 of the Calvin cycle with an equation and in words
6 ATP converts 10 of the 12 G3P 6 RuBPSome G3P will be used to regenerate RuBP so that the cycle can continue This requires ATP from the light dependent reactions Alternatively some G3P will be saved for step 4 of the Calvin cycle
70
describe the carbohydrate glucose synthesis step step 4 of the Calvin cycle with an equation and in words
2 G3P 1 glucoseThe 2 remaining G3P threecarbon molecule that were leftover from step 3 are used to build glucose sixcarbon molecule
71
RuBisCo can also bind _____ in a process called _____
oxygen photorespiration
72
plants in hot and dry environments ____ their stomata to minimize _____ This results in ____ not being able to leave and ____ not being able to enter the leaf
close water loss oxygen carbon dioxide
73
when plants in hot and dry environments _____ their stomata RuBisCo is encouraged to bind _____ and photorespiration starts to occur
close oxygen
74
the byproducts of photorespiration are metabolized by _____ _____
peroxisomes mitochondria
75
what are 2 mechanisms plants have evolved to minimize photorespiration
C4 photosynthesis and CAM crassulacean acid metabolism photosynthesis
76
In the mesophyll cell C4 photosynthesis uses an enzyme called _____ which fixes CO₂ into a threecarbon molecule called _____
PEP carboxylase PEP
77
in C4 photosynthesis CO2 PEP in the presence of PEP carboxylase makes _____ at the mesophyll cell
oxaloacetate
78
in C4 photosynthesis oxaloacetate quickly converts to _____ at the mesophyll cell
malate
79
C4 photosynthesis is called C4 because
both oxaloacetate and malate are 4 carbon compounds
80
in C4 photosynthesis malate is transported from _____ cells to _____ cells
mesophyll bundle sheath
81
the CO₂ released at the bundle sheath cell of C4 photosynthesis can undergo carbon fixation using _____
RuBisCo
82
what is the advantage of bundle sheath cells in C4 photosynthesis
they do not contain as much O₂ so photorespiration is less likely to occur
83
what happens to the threecarbon pyruvate at the bundle sheath cell of C4 photosynthesis
it is shuttled back to the mesophyll cell alongside the hydrolysis of ATP AMP
84
what does pyruvate convert into when back at the mesophyll cell of C4 photosynthesis
PEP
85
C4 photosynthesis occurs in a small percentage of plants living in _____ environments
hot
86
C4 photosynthesis prevents photorespiration through the _____ of carbon dioxide
spatial isolation
87
_____ means that inorganic carbon is transported to a different location to prevent photorespiration
spatial isolation
88
CAM plants use _____ which prevents photorespiration through timing
temporal isolation
89
CAM plants close their stomata during the ___ to prevent transpiration
day
90
At ____ CAM plants have their stomata open allowing carbon dioxide to enter the leaf
night
91
after CO₂ diffuses into the mesophyll of CAM plants at night what happens
PEP carboxylase will takeCO₂ onecarbon PEP threecarbon to produce oxaloacetate fourcarbon which converts to malate fourcarbon
92
what happens to the fourcarbon malate molecule produced in CAM photosynthesis
it is stored in the vacuole of the mesophyll cell for later use
93
in CAM photosynthesis during the next day when the stomata are ______ malate will convert back into ________
closed oxaloacetate
94
the overall advantage is that CAM photosynthesis can proceed during the day while stomata are _____ reducing _____ loss
closed water H₂O
