Deck 13: Photosynthesis

Question 1

The membrane component that mediates the conversion of light energy into chemical energy is called a __________.

A) Chromophore
B) Granum
C) Antenna pigment
D) Stromal lamella
E) Reaction center

Answer 1

E

Question 2

Photosystem I contains _______.

A) P₇₀₀
B) P₆₈₀
C) D₁/D₂ dimer
D) Cyt B₅₅₉
E) All of the above

Answer 2

A

Question 3

PSII is found in the

A) Thylakoid membrane directly exposed to the stroma
B) Thylakoid membrane that is not exposed to the stroma
C) Stroma
D) Inner membrane of chloroplasts
E) All of the above are correct

Answer 3

B

Question 4

The CF₁ component of the ATP synthase

A) Possesses an ATP synthesizing activity
B) Possesses a proton-conducting channel
C) Projects into the stroma
D) Both A and C are correct
E) Both B and C are correct

Question 5

All of the following statements concerning light are true except

A) High frequency radiation such as gamma rays and X-rays, which have long wavelengths, are high energy.
B) A wavelength is the distance from the crest of one wave to the crest of the next wave.
C)  = c/
D) When light interacts with matter, it does so in discrete packets of energy called photons.
E) The intensity of electromagnetic radiation is proportional to a².

Question 6

As long as the spins of two unpaired electrons remain antiparallel, a molecule which has absorbed light energy, is said to be

A) In the ground state
B) An excited chromophore
C) In an excited singlet state
D) Both A and C are correct
E) None of the above are correct

Question 7

In _______ a molecule's excited state decays as it emits a photon.

A) Oxidation-reduction
B) Radiationless decay
C) Resonance energy transfer
D) Both A and C are correct
E) None of the above are correct

Question 8

All of the following statements concerning the oxygen-evolving complex in chloroplasts are true except

A) It is found in PSI
B) It is found in PSII
C) It consists of a "clock" mechanism
D) It consists of five oxidation states
E) The evolution of one O₂ requires the splitting of two waters

Question 9

Which of the following is a component of PSI?

A) D1/D2 dimer
B) Pheophytin a
C) Ferredoxin
D) Plastoquinone
E) Rubisco

Question 10

Pheophytin a is a molecule whose structure is similar to that of ______

A) -carotene
B) Lutein
C) Plastocyanin
D) Chlorophyll
E) Plastoquinone

Question 11

Cyclic electron transport occurs when

A) ATP synthesis is excessive
B) Oxygen evolution is suppressed
C) A chloroplast has a high NADPH/NADP⁺
D) The D₁/D₁ dimer is damaged
E) None of the above are correct

Question 12

In photosynthesis there is

A) Splitting of water to form oxygen
B) Synthesis of sugar
C) Excitation of chromophores
D) Production of a proton gradient
E) All of the above are correct

Question 13

__________allows photosynthesizing cells to reemit photons in a protective overflow mechanism.

A) Oxidation-reduction
B) Radiationless decay
C) Fluorescence
D) Resonance energy transfer
E) Photorespiration

Question 14

The Calvin cycle is sometimes referred to as

A) The dark reactions
B) Light independent reactions
C) Reductive pentose phosphate pathway
D) Both A and B are correct
E) All of the above are correct

Question 15

Ribulose -1,5-bisphosphate carboxylase catalyzes the carboxylation of
Ribulose-1,5-bisphosphate to form

A) One molecule of sucrose
B) One molecule of glucose
C) Two molecules of glyceraldehyde-3-phosphate
D) Two molecules of glycerate-3-phosphate
E) Two molecules of dihydroxyacetone phosphate

Question 16

The reaction in photosynthesis catalyzed by glyceraldehyde-3-phosphate dehydrogenase is similar to a reaction in

A) Sucrose synthesis
B) Gluconeogenesis
C) Citric acid cycle
D) Glycogenesis
E) Glycogenolysis

Question 17

The net production of "fixed" carbon in the Calvin cycle is

A) One molecule of glyceraldehyde-3-phosphate
B) One molecule of glycerate-3-phosphate
C) Two molecules of glycerate-3-phosphate
D) Two molecules of eythrose-4-phosphate
E) One molecule of ribulose-1,5-bisphosphate

Question 18

Most of the carbon translocated throughout plants is in the form of

A) Starch
B) Sucrose
C) Ribulose-1,5-bisphosphate
D) Glyceraldehyde-3-phosphate
E) Dihydroxyacetone phosphate

Question 19

During photosynthesis light energy captured by an organism's photosystem is transduced into which of the following?

A) ATP
B) Water
C) Oxygen
D) Carbon dioxide
E) Glucose

Question 20

The process of photorespiration is suppressed in

A) C3 metabolism
B) C4 metabolism
C) CAM metabolism
D) Both B and C are correct
E) All of the above are correct

Question 21

Phosphoenolpyruvate carboxylase catalyzes a key reaction in

A) Sucrose metabolism
B) The Calvin cycle
C) The Hatch-Slack pathway
D) Gluconeogenisis
E) The PCR cycle

Question 22

Features of light regulation of photosynthesis-associated enzymes include all of the following except __________.

A) pH
B) Phytochrome
C) Mg⁺⁺ concentration
D) Fluorescence
E) Ferredoxin-threodoxin system

Question 23

The active form of phytochrome is ________.

A) P_r
B) P_fr
C) Blue form
D) Both A and C are correct
E) Both B and C are correct

Question 24

Examples of phytochrome-mediated process include all of the following except

A) Seed germination
B) Chloroplast development
C) Stem elongation
D) Intracellular Ca⁺⁺ level changes
E) None of the above are correct

Question 25

When adequate light is available, the overall rate of photosynthesis is dependent on the rate of

A) Ca⁺⁺ levels
B) Sucrose accumulation
C) Starch accumulation
D) Phytochrome concentration
E) Carbon dioxide fixation

Question 26

In addition to an inner and outer membrane chloroplasts contain a third membrane called

A) Thylakoid lumen
B) Stroma
C) Thylakoid membrane
D) Stromal llamella
E) Grana

Question 27

In photorespiration which of the following molecules are consumed?

A) Carbon dioxide
B) Oxygen
C) NADH
D) ATP
E) B, C, and D are correct

Question 28

The chlorophylls absorb little light between

A) 400 and 500 nm
B) 500 and 600 nm
C) 600 and 700 nm
D) Bot A and B are correct
E) None of the above is correct

Question 29

The most abundant enzyme on earth is

A) Alcohol dehydrogenase
B) Rubisco
C) Sucrose synthase
D) Citrate synthase
E) Glucose-6-phosphate dehydrogenase

Question 30

Which of the following statements concerning photorespiration is not true?

A) High oxygen concentration and high temperatures promote photorespiration.
B) Photorespiration is a serious problem of C4 plants in hot dry environments.
C) When the rates of carbon dioxide release and fixation are equal, the carbon dioxide compensation point has been reached.
D) Photorespiration is depressed by carbon dioxide concentrations above 0.2%.
E) The lower the value of the carbon dioxide compensation point the less photorespiration takes place.

Question 31

There are three mechanisms for fixing carbon dioxide in plants: C4 metabolism, C3 photosynthesis and ___________.

A) Photorespiration
B) Calvin Cycle
C) Crassulacean acid metabolism
D) Light independent reaction
E) Dark reaction

Question 32

In C4 plants carbon dioxide is initially incorporated into _________.

A) Oxaloacetate
B) Malate
C) Pyruvate
D) Succinate
E) Acetate

Question 33

CAM plants are mostly

A) Grasses
B) Succulents
C) Conifers
D) Blue green algae
E) Both A and C are correct

Question 34

The principal regulator of photosynthesis is ___________.

A) Light
B) Oxygen
C) Carbon dioxide
D) Oxaloacetate
E) Water

Question 35

During the light-dependent reactions which of the following takes place?

A) Oxygen is evolved
B) ATP is produced
C) NADPH is produced
D) Carbon dioxide is fixed
E) Both A and B are correct

Question 36

The most important enzyme in photosynthesis is ____________.

A) Ribulose-1,5-bisphosphate carboxylase
B) ATP synthase
C) Pheophytin
D) Ferredoxin- NADP oxidoreductase
E) Dehydrogenase

Question 37

What is the final electron acceptor of photosynthesis?

A) Carbon dioxide
B) Water
C) Oxygen
D) Glucose
E) ATP

Question 38

The principal metals involved in photosynthesis include all of the following except

A) Mn
B) Ca
C) Mg
D) Fe
E) Cu

Question 39

The three phases of the Calvin Cycle are carbon fixation, regeneration and __________

A) Photorespiration
B) ATP synthesis
C) Reduction
D) NADP synthesis
E) Both A and B are correct

Question 40

Which of the following is not a biofuel

A) Ethanol from petroleum
B) Biodiesel
C) Hydrogen
D) Methane
E) A and D

Question 41

In photosynthesis captured light energy is used to initially synthesize

A) ATP
B) NADH
C) NADPH
D) Glucose
E) A and C

Question 42

Which of the following is not found in the water splitting complex?

A) Manganese
B) Calcium
C) Magnesium
D) Amino acid residues
E) A and B

Question 43

In the reduction phase of the Calvin Cycle aldolase catalyzes the reaction between dihydroxyacetone and glyceraldehyde-3-phospate to form

A) Glucose
B) Fructose-1,6-bisphosphate
C) Dihydroxyacetone phosphate
D) Fructose-6-phosphate
E) Fructose-1-phosphate

Question 44

Which of the following is not a consequence of global warming as predicted by the vast majority of the world's climate scientists?

A) Increased frequency of insect born diseases
B) Increased intensity of drought
C) Food shortages
D) Higher temperatures
E) Drop in ocean levels

Question 45

Which of the following fuels cannot be carbon neutral?

A) Hydrogen
B) Natural gas
C) Ethanol produced by fermentation
D) Biodiesel
E) A and B

Question 46

What processes occur in the light-dependent reaction of photosynthesis?

Question 47

What processes occur in the light-independent reaction of photosynthesis?

Question 48

What is a Rieske protein and what is its function?

Question 49

What is the most significant contribution of early photosynthetic organisms to Earth's environment?

Question 50

List the three primary photosynthetic pigments and describe the role of each in photosynthesis.

Question 51

List three ways that chloroplasts resemble mitochondria.

Question 52

What is lutein?

Question 53

What is the final electron acceptor in photosynthesis when the NADPH/NADP⁺ ratio is low?

Question 54

What are the principal products that are produced during the light-dependent reactions of photosynthesis?

Question 55

What is the net production of one cycle of the dark reactions?

Question 56

Carbon dioxide and water are substrates for photosynthesis. Which of these is the source of molecular oxygen?

Question 57

Why is the oxygen-evolving system referred to as a clock?

Question 58

In reference to photosynthesis what is a special pair and how does it function?

Question 59

Why is the term dark reactions misleading?

Question 60

Plants actively engaged in photosynthesis also evolve carbon dioxide. Explain.

Question 61

List four consequences of global warming.

Question 62

List three criteria for sustainable biofuel production.

Question 63

List the types of metal that are components of the photosynthesis mechanisms. What functions do they serve?

Question 64

Where does carbon dioxide fixation take place in the cell?

Question 65

Why does carbon dioxide repress photorespiration?

Question 66

What are triose phosphates? Where are they formed in plant carbohydrate metabolism?

Question 67

If the rate of photosynthesis is plotted versus the incident wavelength of light, an action spectrum is obtained. How can the action spectrum provide information about the nature of the light-absorbing pigments involved in photosynthesis?

Question 68

What is the net reaction for photosynthesis? What is the origin of the oxygen molecules in glucose?

Question 69

Deforestation greatly decreases the plant biomass in any area. What impact will deforestation have on the quality of life in the region?

Question 70

Explain the following observation. When a photosynthetic system is exposed to a brief flash of light no oxygen is evolved. It is only after several bursts of light that oxygen is evolved.

Question 71

If a C3 plant and a C4 plant are placed in separate sealed containers and provided with adequate light and water, both will survive. If both plants are placed in a single sealed container the C3 plant will die. Explain.

Question 72

Herbicides that act by promoting photorespiration are lethal to C3 plants but do not affect C4 plants. Explain.

Question 73

What is the end product of photosynthesis when hydrogen sulfide is the source of hydrogen atoms?

Question 74

What effect would you expect dinitrophenol to have on photosynthesis?

Question 75

The burning of fossil fuels releases carbon dioxide into the atmosphere and is detrimental to Earth's ecosystems. Explain why the use of biofuels, which also release carbon dioxide into the atmosphere, is an improvement over fossil fuels.

Question 76

In the absence of carbon dioxide, chlorophyll fluoresces. How does carbon dioxide prevent this fluorescence?