Deck 9: Photosynthesis: Capturing Light Energy

Question 1

Which part of the chlorophyll molecule is responsible for absorbing light?

A) Methyl group
B) Porphyrin ring
C) Magnesium ion
D) Phosphate group
E) Long hydrocarbon side chain

Answer 1

B

Question 2

Which of these absorbs light primarily in the blue and red regions of the visible spectrum and is the main pigment of photosynthesis?

A) Chloroadenosine
B) Chlorohydrate
C) Chlorpromazine
D) Chloroquine
E) Chlorophyll

Answer 2

E

Question 3

Figure 9-1 ​

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What is the primary function of the leaf structure labeled as 5 in the accompanying figure?

A) Food storage
B) Gas exchange
C) Photosynthesis
D) Nutrient absorption
E) Water transportation

Answer 3

B

Question 4

Figure 9-2 ​

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According to the graph in the accompanying figure, chlorophyll absorbs light most strongly in what region of the electromagnetic spectrum?

A) UV and red wavelengths
B) Red and blue wavelengths
C) Blue and green wavelengths
D) Green and yellow wavelengths
E) UV and infrared wavelengths

Question 5

The action spectrum of photosynthesis best matches the absorption spectrum of

A) ATP.
B) NADPH.
C) carotenoids.
D) carbohydrates.
E) chlorophylls a and b .

Question 6

What happens in the second phase of the Calvin cycle?

A) A molecule of CO₂ reacts with a phosphorylated five-carbon compound, ribulose bisphosphate.
B) Two G3P molecules are removed from the cycle.
C) ATP and NADPH are used to convert the PGA molecules to glyceraldehyde-3-phosphate.
D) Thirty carbons and their associated atoms become rearranged into six molecules of ribulose phosphate.
E) RuBP molecules begin the process of CO₂ fixation.

Question 7

When an electron returns to its ground state, energy will be released as heat or as an emission of light, known as

A) fluorescence.
B) UV radiation.
C) action spectrum.
D) photoelectron hydrolysis.
E) photoelectron degradation.

Question 8

Figure 9-1 ​

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Using the labels in the accompanying figure, where are chloroplasts found in the greatest density?

A) 1 and 2
B) 3 and 4
C) 4 and 5
D) 6 and 7
E) 7 and 8

Question 9

What is the process by which light energy is converted into the stored chemical energy of organic molecules?

A) Diffusion
B) Endocytosis
C) Respiration
D) Fermentation
E) Photosynthesis

Question 10

Which type of electromagnetic waves has the shortest wavelength?

A) Ultraviolet
B) Radio waves
C) Microwaves
D) Gamma waves
E) Visible green light

Question 11

An electron absorbs a photon of light energy and becomes energized; the electron shifts from a ____ atomic orbital to a __________ atomic orbital.

A) fluorescing; ground state
B) ground state; lower energy
C) lower energy; higher energy
D) higher energy; lower energy
E) ground state; different ground state

Question 12

Figure 9-2 ​

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The graph in the accompanying figure represents the

A) electromagnetic spectrum.
B) action spectrum of photosynthesis.
C) process of cyclic electron transport.
D) process of noncyclic electron transport.
E) absorption spectra for chlorophylls a and b.

Question 13

By definition, substances that absorb visible light are called

A) photons.
B) pigments.
C) porphyrins.
D) nucleotides.
E) hydrocarbons.

Question 14

Which of the following are accessory photosynthetic pigments that expand the spectrum of light to provide energy for photosynthesis?

A) Carotenoids only
B) Chlorophyll a only
C) Chlorophyll b only
D) Carotenoids and chlorophyll a
E) Carotenoids and chlorophyll b

Question 15

What color does chlorophyll reflect?

A) Red
B) Blue
C) Green
D) Violet
E) Yellow

Question 16

What is the fluid-filled sac within the inner membrane of a chloroplast called?

A) Grana
B) Lumen
C) Stroma
D) Thylakoid
E) Electron acceptor

Question 17

A group of thylakoid discs make up what part of the chloroplast?

A) Lumen
B) Stroma
C) Granum
D) Vacuole
E) Mesophyll layer

Question 18

A chlorophyll molecule has a porphyrin ring containing a single atom of

A) manganese.
B) magnesium.
C) phosphorus.
D) nitrogen.
E) iron.

Question 19

Chlorophyll and accessory photosynthetic pigments are associated with which part of the chloroplast?

A) Stroma
B) Thylakoid lumen
C) Thylakoid membranes
D) Mesophyll membranes
E) Light reaction centers of the stroma lamellae

Question 20

The energy of a(n) ____ is inversely proportional to its wavelength.

A) radon
B) proton
C) photon
D) neutron
E) electron

Question 21

During which phase of photosynthesis is ATP and NADPH synthesized?

A) Glycolysis
B) Citric acid cycle
C) Light-dependent phase
D) Light-independent phase
E) Carbon fixation reactions

Question 22

Animals, fungi, and most prokaryotes are known as ________.

A) chemoheterotrophs
B) photoautotrophs
C) universal consumers
D) primary producers
E) autophotorespirators

Question 23

Which photosynthetic unit consists of a pair of chlorophyll a molecules with an absorption peak of 700 nm?

A) Photolysis
B) Calvin cycle
C) Photosystem I
D) Antenna complex
E) Photosystem II

Question 24

How are chlorophyll molecules attached to thylakoid membranes?

A) By a magnesium ion
B) With a porphyrin ring
C) With a methyl group
D) By a hydroxide group
E) By a long hydrocarbon side chain

Question 25

What are the two phases of photosynthesis?

A) Chemiosmosis and photochemical reactions
B) Carbon reduction reactions and oxidation reactions
C) Light-dependent reactions and carbon fixation reactions
D) Carbon fixation reactions and oxygen fixation reactions
E) Light-independent reactions and carbon fixation reactions

Question 26

During photosynthesis, ____ is reduced and ____ is oxidized.

A) O₂; H₂O
B) CO₂; H₂O
C) O₂; C₆H₁₂O₆
D) H₂O; C₆H₁₂O₆
E) CO₂; C₆H₁₂O₆

Question 27

The synthesis of ATP during photosynthesis or respiration is the result of what process?

A) Oxidation of NADPH
B) Phosphorylation of ATP
C) Phosphorylation of ADP
D) Phosphorylation of G3P
E) Photophosphorylation of AMP

Question 28

Which process not only yields electrons that replenish photosystems I and II, but also is the source of almost all the oxygen in Earth's atmosphere?

A) Glycolysis
B) Photolysis
C) Calvin cycle
D) CAM pathway
E) Noncyclic electron transport

Question 29

How many electrons are needed to reduce one molecule of NADP⁺ to NADPH?

A) One
B) Two
C) Three
D) Four
E) Five

Question 30

Figure 9-3 ​

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Where is NADPH formed in the accompanying diagram?

A) F
B) 4
C) 3
D) 2
E) B

Question 31

ATP is formed when ____ the thylakoid lumen.

A) hydrogen ions enter
B) hydrogen ions leave
C) electrons enter
D) electrons leave
E) water is split in

Question 32

In which part of the chloroplast do the carbon fixation reactions take place?

A) Lumen
B) Stroma
C) Granum
D) Mesophyll
E) Thylakoids

Question 33

ATP synthesis during the light-dependent reactions occurs by which process?

A) Diffusion
B) Photolysis
C) Chemiosmosis
D) Phosphorylation
E) Cyclic electron transport

Question 34

Land plants, algae, and certain prokaryotes are known as _______.

A) chemoheterotrophs
B) photoautotrophs
C) universal consumers
D) primary producers
E) autophotorespirators

Question 35

Thylakoid membranes are involved in ____ synthesis.

A) glucose
B) NADP⁺
C) ATP
D) RuBP
E) PEP

Question 36

What is the ultimate source of electrons for noncyclic electron transport, and thus photosynthesis?

A) ATP
B) Water
C) NADP⁺
D) Oxygen
E) Chlorophyll

Question 37

Which best summarizes the overall reactions of photosynthesis?

A) 6CO₂ + 12H₂O → C₆H₁₂O₆ + 12O_2.
B) C₆H₁₂O₆ + 6O₂ + 6H₂O → 6CO₂ + 12H₂O
C) 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O
D) 12CO₂ + 6H₂O → C₆H₁₂O₆ + 12O₂ + 6H₂O
E) 6H₂CO₃ + 6H₂O → C₆H₁₂O₆ + C₆H₁₂O₆ + 6H₂O + 6O₂

Question 38

What are the reactants of the light-dependent reactions of photosynthesis?

A) H₂O, ADP, and NADP+
B) CO₂, ADP, and NADP+
C) H₂O, ATP, and NADPH
D) CO₂, ADP, and NADPH
E) H₂O, CO₂, and NADP+

Question 39

Where is the electron transport chain of photosynthesis located?

A) Cristae
B) Mitochondria
C) Chloroplast stroma
D) Thylakoid membrane
E) Outer chloroplast membrane

Question 40

Figure 9-3 ​

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Carbon is fixed in which part of the accompanying diagram?

A) A
B) G
C) 4
D) 2
E) 1

Question 41

What are the reactants of the Calvin cycle?

A) CO₂, H₂O, and ATP
B) CO₂, ADP, and NADP+
C) CO₂, ATP, and NADPH
D) H ₂ O, ATP, and NADPH
E) H ₂ O, ATP, and NADP+

Question 42

Plants that live in hot dry climates, like corn or maize, use the C₄ pathway. Briefly describe this pathway and explain how this adaptation allows these plants to increase the efficiency of photosynthesis in these climates.

Question 43

Which of the following would be classified as a CAM plant?

A) Rose
B) Crocus
C) Orchid
D) Daffodil
E) Chrysanthemum

Question 44

The product of the Calvin cycle that is of greatest practical importance to the plant is carbohydrate.

Question 45

What is the first step in the Calvin cycle?

A) O₂ attaches to CO₂.
B) O₂ attaches to G3P.
C) CO₂ attaches to RuBP.
D) CO₂ attaches to Rubisco.
E) CO₂ attaches to phosphoglycerate.

Question 46

Which organism would be classified as a chemoautotroph?

A) Cactus
B) Lichen
C) Oak tree
D) Green algae
E) Nitrogen-fixing bacteria

Question 47

The part of a chlorophyll molecule that absorbs light energy is the porphyrin ring.

Question 48

At night, CAM plants incorporate CO₂ into ____, which is stored in the ____ of their cells.

A) fructose; vacuoles
B) malate; vacuoles
C) glucose; starch granules
D) pyruvate; starch granules
E) acetyl CoA; mitochondria

Question 49

Surrounding the grana is the thylakoid lumen.

Question 50

In photosynthesis, the oxygen atoms released as O₂ comes from CO₂ .

Question 51

The establishment of the proton gradient is a very important part of photosynthesis. Briefly explain how the gradient is formed, where it occurs within the cell, and what is its role in photosynthesis.

Question 52

In C₃ plants, the ____ are typically closed at night and open during the daytime to allow for gas exchange.

A) grana
B) stomata
C) cuticles
D) epidermis
E) spongy mesophyll

Question 53

The photolysis of water occurs in conjunction with photosystem I.

Question 54

In C₄ plants, reactions that fix CO₂ into four-carbon compounds occur in what type of cells?

A) Guard cells
B) Xylem cells
C) Epidermal cells
D) Mesophyll cells
E) Bundle sheath cells

Question 55

How many carbon fixation reactions make up the Calvin cycle?

A) 2
B) 3
C) 5
D) 10
E) 13

Question 56

Ribulose phosphate is synthesized from which molecule?

A) CO₂
B) G3P
C) RuBP
D) NADP⁺
E) Pyruvate

Question 57

Which is the energy source that drives the Calvin cycle?

A) ATP only
B) ADP only
C) G3P only
D) ADP and G3P
E) ATP and NADPH

Question 58

An absorption spectrum indicates the relative effectiveness of different wavelengths of light in powering photosynthesis.

Question 59

Compare the cyclic and noncyclic electron transport pathways of photosynthesis.

Question 60

Diagram and label the internal structure of a chloroplast. Briefly describe the function of each structure.

Question 61

ATP is generated when protons flow through the cytochrome complex in the thylakoid membrane.

Question 63

At a plant's light compensation point the rate of photosynthesis is greater than the rate of respiration.

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Question 66

Photorespiration is a wasteful process that could be largely avoided if rubisco would bind only CO₂.

Question 68

Most plants are known as photoheterotrophs.

Question 70

Propose an appropriate solvent to be used in the extraction of photosynthetic pigments from chloroplasts. Explain your choice.

Question 71

Cyclic electron transport is different from noncyclic electron transport in that cyclic electron transport produces NADPH.

Question 73

Photosynthesis and aerobic respiration are both important processes for the generation of energy in organisms. However, the two processes are distinct. Explain the differences and similarities between the two processes.

Question 74

When photosynthetic pigments are extracted from the chloroplasts of green plants, they have a higher tendency to fluoresce than pigments within intact chloroplasts. Explain this phenomenon.

Question 75

CAM plants open their stomata at night, admitting CO₂ while minimizing water loss.

Question 78

Even though the steps of photosynthesis that produce sugar molecules are part of the carbon fixation reactions, the light-dependent reactions are essential for sugar synthesis. Explain the role of the light-dependent reactions in the formation of the end products of photosynthesis.