Worksheetsphotosynthesis
Total questions: 108
Worksheet time: 56mins
Name
Class
Date
1.
_____ are organisms (like humans) that obtain chemical energy from the food they eat
a)
heterotrophs
2.
_____ organisms are capable of making their own food
a)
autotrophic
3.
_____ (like plants) capture solar energy and convert it to chemical energy by photosynthesis
a)
photoautotrophs
4.
_____ creates chemical energy which is passed up the food web to all organisms
a)
photosynthesis
5.
photosynthesis releases _____, which is crucial for aerobic cellular respiration
a)
oxygen
6.
photosynthesis reduces _____ from the atmosphere
a)
carbon dioxide
7.
_____ occurs when inorganic carbon is incorporated into an organic molecule (like a sugar molecule)
a)
carbon fixation
8.
write the overall chemical equation for photosynthesis:
a)
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
9.
The two stages of photosynthesis are the _________ and the ____________
a)
light dependent reactions; Calvin cycle
10.
light dependent reactions produce _____ and _____
a)
ATP
b)
NADPH
11.
the Calvin cycle (or light independent reaction) uses energy stored in _____ and _____
a)
ATP
b)
NADPH
12.
photosynthesis stores solar energy in glucose chemical bonds - how do plants then use that energy?
a)
aerobic cellular respiration
13.
photosynthesis has a positive Gibbs free energy (+ ΔG), so it is _____ and _____
a)
non-spontaneous
b)
endergonic
14.
the overall reactions of aerobic cellular respiration and photosynthesis are ______
a)
opposites
15.
solar energy is input to photosynthesis to convert 6 _____ & 6 _____ to 1 _____ and 6 _____
a)
CO2; H2O; Glucose; O2
16.
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
17.
ATP from the light dependent reactions is not used to _____
a)
power the cell
18.
ATP from the light dependent reactions is consumed to power the _____, which makes glucose
a)
Calvin cycle
19.
_____ tissue is the outer layer of cells - what is its function?
a)
epidermis; it provides protection and prevents water loss
20.
_____ mesophyll cells conduct most photosynthesis
a)
palisade
21.
palisade mesophyll cells contain many _____, and are well organized as a single layer below the _____
a)
chloroplasts; upper epidermis
22.
spongy mesophyll cells conduct some photosynthesis, but not as much as the _____ cells
a)
palisade mesophyll
23.
spongy mesophyll cells have few _____
a)
chloroplasts
24.
spongy mesophyll cells are found toward the _____
a)
bottom of the leaf
25.
gaps between spongy mesophyll cells facilitate the movement of _____
a)
gases
26.
stomata are pores mainly found in the _____ of leaves and they are the site of _____
a)
bottoms; atmospheric gas exchange
27.
_____ surround stomata, and they control whether the stomata are open or closed
a)
guard cells
28.
_____ are dual membrane organelles found in plants and photosynthetic algae
a)
chloroplasts
29.
organisms with chloroplasts for photosynthesis will have _____ for cellular respiration too
a)
mitochondria
30.
chloroplasts contain thylakoids, where _____ occur
a)
light dependent reactions
31.
both stages of photosynthesis occur within _____
a)
chloroplasts
32.
_____ are photosynthetic organisms that do not have a chloroplast
a)
cyanobacteria
33.
the _____ is the fluid material that fills area inside the inner membrane of a chloroplast
a)
stroma
34.
the Calvin cycle occurs in the _____ of the chloroplast
a)
stroma
35.
_____ are phospholipid bilayer structured organelles that are suspended within the stroma
a)
thylakoids
36.
Light dependent reactions occur in the _______ of chloroplasts
a)
thylakoid membranes
37.
an entire stack of thylakoids is called a _____
a)
granum
38.
a junction between two grana is called a _____
a)
lamella
39.
protons (H⁺) for chloroplast chemiosmosis accumulate in the _____
a)
thylakoid lumen
40.
ATP synthesis in the chloroplast occurs as protons (H⁺) flow from the _____ to the _____
a)
thylakoid lumen; stroma
41.
thylakoid membranes have _____ to capture photons
a)
photosystems
42.
photosystems contain special _____, including chlorophylls and carotenoids
a)
pigments
43.
photosystem _____ are directly responsible for absorbing photons
a)
pigments
44.
what are the 2 important photosystems for photosynthesis?
a)
photosystem I and II
45.
photosystems I and II each have a _____ of chlorophyll molecules located in the center of the protein. This is known as the _____
a)
special pair; reaction center
46.
the special pair of chlorophyll molecules in photosystem I is known as _____
a)
P700
47.
the special pair of chlorophyll molecules in photosystem II is known as _____
a)
P680
48.
_____ of water involves the splitting of H₂O molecules into electrons (e⁻), protons (H⁺), and oxygen gas (O₂)
a)
photolysis
49.
where do the electrons (e⁻) from photolysis travel to in photosystem II?
a)
they travel to the special pair at P680 of photosystem II (the reaction center)
50.
When photons reach photosystem II, they will excite electrons (e⁻) at the _______. This causes the electrons (e⁻) to be passed to a primary __________
a)
reaction center; electron accepter
51.
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.
a)
pumping protons (H⁺); thylakoid lumen
52.
after traveling down the primary electron transport chain (ETC) of the thylakoid membrane, electrons (e⁻) will reach _____
a)
photosystem I (P700 special pair - reaction center)
53.
what is the purpose of the secondary ETC (following PSI) in the light-dependent reactions?
a)
to reduce NADP+ --> NADPH using NADP+ reductase
54.
describe the general pathway of non-cyclic photophosphorylation:
a)
photolysis → Photosystem II (P680) → primary ETC→ Photosystem I (P700) → secondary ETC → NADP+ reductase to make NADPH
55.
non-cyclic photophosphorylation requires light (photons) to be absorbed _____ - one time at each photosystem
a)
twice
56.
electrons (e⁻) do not travel to the _____ in cyclic photophosphorylation, thus _____ is not produced
a)
second ETC; NADPH
57.
describe the general pathway for cyclic photophosphorylation:
a)
photolysis → Photosystem II (P680) → primary ETC → Photosystem I (P700) → primary ETC → Photosystem I (P700) → etc.
58.
what are the products of the light dependent reactions?
a)
ATP and NADPH, O₂ (waste product)
59.
'normal' photosynthesis can also be called _____ because the carbon fixation step of the Calvin cycle produces three-carbon molecules
a)
C3 photosynthesis
60.
what are the products of the Calvin cycle?
a)
Glucose, ADP, NADP+
61.
the Calvin cycle is sometimes referred to as the _____ because it does not use light energy directly
a)
light independent reactions
62.
the _____ cannot occur without light because it is dependent on the high energy molecules produced from the light reaction (ATP and NADPH)
a)
Calvin cycle
63.
the Calvin cycle fixes _____ into _____
a)
inorganic carbon dioxide; organic glucose sugars
64.
the Calvin cycle must accept _____ CO₂ molecules to synthesize _____ glucose molecule.
a)
6 CO₂; 1 C₆H₁₂O₆ (glucose)
65.
list the 4 steps of the Calvin cycle in order:
a)
carbon fixation
b)
reduction of a 3-carbon intermediate;
c)
regeneration of RuBP
d)
carbohydrate synthesis
66.
describe the carbon fixation step (step 1) of the Calvin cycle with an equation and in words:
a)
6 CO₂ + 6 RuBP → 12 PGA
b)
catalyzed by RuBisCo
c)
CO₂ (one-carbon) combines with RuBP (five-carbons) to produce a six-carbon molecule that splits into 2 PGA molecules (three-carbons per PGA molecule)
67.
describe the reduction step (step 2) of the Calvin cycle with an equation and in words:
a)
12 ATP + 12 NADPH converts 12 PGA → 12 G-3-P
b)
ATP from the light dependent reactions will phosphorylate the PGA from carbon fixation to produce another three-carbon intermediate.
c)
NADPH from the light dependent reactions reduces the three-carbon intermediate to produce G3P sugars
68.
describe the regeneration step (step 3) of the Calvin cycle with an equation and in words:
a)
6 ATP converts 10 (of the 12) G-3-P → 6 RuBP
b)
Some G3P will be used to regenerate RuBP so that the cycle can continue. This requires ATP from the light dependent reactions.
c)
Alternatively, some G3P will be saved for step 4 of the Calvin cycle.
69.
describe the carbohydrate (glucose) synthesis step (step 4) of the Calvin cycle with an equation and in words:
a)
2 G3P → 1 glucose
b)
The 2 remaining G3P (three-carbon molecule) that were leftover from step 3 are used to build glucose (six-carbon molecule).
70.
RuBisCo can also bind _____ in a process called _____
a)
oxygen; photorespiration
71.
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.
a)
close; water loss; oxygen; carbon dioxide
72.
when plants in hot and dry environments _____ their stomata, RuBisCo is encouraged to bind _____ and photorespiration starts to occur
a)
close; oxygen
73.
the byproducts of photorespiration are metabolized by _____ & _____
a)
peroxisomes; mitochondria
74.
what are 2 mechanisms plants have evolved to minimize photorespiration?
a)
C4 photosynthesis and CAM (crassulacean acid metabolism) photosynthesis
75.
In the mesophyll cell, C4 photosynthesis uses an enzyme called _____, which fixes CO₂ into a three-carbon molecule called _____
a)
PEP carboxylase; PEP
76.
in C4 photosynthesis, CO2 + PEP in the presence of PEP carboxylase makes _____ at the mesophyll cell
a)
oxaloacetate
77.
in C4 photosynthesis, oxaloacetate quickly converts to _____ at the mesophyll cell
a)
malate
78.
C4 photosynthesis is called C4 because..?
a)
both oxaloacetate and malate are 4 carbon compounds
79.
in C4 photosynthesis, malate is transported from _____ cells to _____ cells
a)
mesophyll; bundle sheath
80.
the CO₂ released at the bundle sheath cell of C4 photosynthesis can undergo carbon fixation using _____
a)
RuBisCo
81.
what is the advantage of bundle sheath cells in C4 photosynthesis?
a)
they do not contain as much O₂, so photorespiration is less likely to occur
82.
what happens to the three-carbon pyruvate at the bundle sheath cell of C4 photosynthesis?
a)
it is shuttled back to the mesophyll cell alongside the hydrolysis of ATP → AMP
83.
what does pyruvate convert into when back at the mesophyll cell of C4 photosynthesis?
a)
PEP
84.
C4 photosynthesis occurs in a small percentage of plants living in _____ environments
a)
hot
85.
C4 photosynthesis prevents photorespiration through the _____ of carbon dioxide
a)
spatial isolation
86.
_____ means that inorganic carbon is transported to a different location to prevent photorespiration
a)
spatial isolation
87.
CAM plants use _____, which prevents photorespiration through timing
a)
temporal isolation
88.
CAM plants close their stomata during the ___ to prevent transpiration
a)
day
89.
At ____, CAM plants have their stomata open, allowing carbon dioxide to enter the leaf
a)
night
90.
after CO₂ diffuses into the mesophyll of CAM plants (at night), what happens?
a)
PEP carboxylase will take CO₂ (one-carbon) + PEP (three-carbon) to produce oxaloacetate (four-carbon), which converts to malate (four-carbon)
91.
what happens to the four-carbon malate molecule produced in CAM photosynthesis?
a)
it is stored in the vacuole of the mesophyll cell for later use
92.
in CAM photosynthesis, during the next day when the stomata are ______, malate will convert back into ________
a)
closed; oxaloacetate
93.
the overall advantage is that CAM photosynthesis can proceed during the day while stomata are _____ (reducing _____ loss)
a)
closed; water (H₂O)
94.
- Most life on Earth depends on photosynthesis.
a)
The process is carried out by plants, algae, and some types of bacteria, which capture energy from sunlight to produce oxygen (O2) and chemical energy stored in glucose (a sugar).
b)
Herbivores then obtain this energy by eating plants, and carnivores obtain it by eating herbivores.
95.
- During photosynthesis
a)
plants take in carbon dioxide (CO2) and water (H2O) from the air and soil.
b)
Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons.
c)
This transforms the water into oxygen and the carbon dioxide into glucose.
d)
The plant then releases the oxygen back into the air, and stores energy within the glucose molecules.
96.
- Inside the plant cell are small organelles called chloroplasts,
a)
which store the energy of sunlight.
97.
Within the thylakoid membranes of the chloroplast is
a)
a light-absorbing pigment called chlorophyll, (which is responsible for giving the plant its green color).
98.
During photosynthesis,
a)
chlorophyll absorbs energy from blue- and red-light waves, and reflects green-light waves, making the plant appear green.
99.
- While there are many steps behind the process of photosynthesis, it can be broken down into two major stages:
a)
light-dependent reactions
b)
light-independent reactions.
100.
The light-dependent reaction takes place within the
a)
thylakoid membrane and requires a steady stream of sunlight, hence the name light-dependent reaction
101.
The chlorophyll absorbs energy from the light waves
a)
which is converted into chemical energy in the form of the molecules ATP and NADPH.
102.
The light-independent stage, also known as the Calvin Cycle
a)
takes place in the stroma, the space between the thylakoid membranes and the chloroplast membranes, and does not require light, hence the name light-independent reaction. During this stage, energy from the ATP and NADPH molecules is used to assemble carbohydrate molecules, like glucose, from carbon dioxide.
103.
Not all forms of photosynthesis are created equal, however.
a)
There are different types of photosynthesis, including C3 photosynthesis and C4 photosynthesis.
104.
C3 photosynthesis is used by the majority of plants.
a)
It involves producing a three-carbon compound called 3-phosphoglyceric acid during the Calvin Cycle, which goes on to become glucose.
105.
C4 photosynthesis, on the other hand, produces a four-carbon intermediate compound,
a)
which splits into carbon dioxide and a three-carbon compound during the Calvin Cycle. A benefit of C4 photosynthesis is that by producing higher levels of carbon, it allows plants to thrive in environments without much light or water.
106.
photosynthesis, Process by which green plants and certain other organisms transform light into chemical energy. In green plants, light energy is captured by chlorophyll in the chloroplasts of the leaves and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds (simple and complex sugars) that are the basis of both plant and animal life. Photosynthesis is crucial for maintaining life on Earth (if it ceased) there would soon be little food or other organic matter on the planet, and most types of organisms would disappear.
a)
summary
107.
Photosynthesis consists of
a)
a number of photochemical and enzymatic reactions.
108.
photosynthesis occurs in two stages.
a)
During the light-dependent stage ("light" reactions), chlorophyll absorbs light energy, which excites some electrons in the pigment molecules to higher energy levels. these leave the chlorophyll and pass along a series of molecules, generating formation of NADPH (an enzyme) and high-energy ATP molecules. Oxygen, released as a by-product, passes into the atmosphere through pores in the leaves. NADPH and ATP drive the second stage, the "dark" reactions (or Calvin cycle, discovered by Melvin Calvin), which do not require light. During this stage glucose is generated using atmospheric carbon dioxide.
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