Biology Ch. 10

Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.

Photosystem I

_____ splits water into 1/2 O2, H+, and e- .

Photosystem II

Chlorophyll can be found in _____.

Photosystems I and II

Where does the Calvin cycle occur?

Stroma

_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.

The Electron Transport Chain

The ultimate source of energy to support most life on Earth is _____. A. sunlight B. the carbon cycle C. photosynthetic plants D. chemosynthetic microbes E. geothermal heat

A

True or false? The light-dependent reactions of photosynthesis use water and produce oxygen. A. True B. False

A

What is the biological significance of the light-independent reactions of photosynthesis? A. They convert carbon dioxide to sugar. B. They generate ATP and NADPH. C. They make oxygen. D. They convert ATP to sugar.

A

What is the importance of the light-independent reactions in terms of carbon flow in the biosphere? A. The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars. B. The light-independent reactions use CO2 to make ATP. C. The light-independent reactions turn sugar into ATP for energy. D. The light-independent reactions turn glucose, a sugar, into CO2 gas.

A

Which of these equations best summarizes photosynthesis? A. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 B. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy C. H2O → 2 H+ + 1/2 O2 + 2e- D. 6 CO2 + 6 O2 → C6H12O6 + 6 H2O E. C6H12O6 + 6 O2 → 6 CO2 + 12 H2O

A

Which set of reactions uses H2O and produces O2? A. The light-dependent reactions B. The light-independent reactions

A

Which term describes ATP production resulting from the capture of light energy by chlorophyll? A. Photophosphorylation B. Oxidative phosphorylation C. Dephosphorylation D. Substrate-level phosphorylation

A

_____ has a longer wavelength than _____. A. Red ... green B. Violet ... blue C. Green ... yellow D. Blue ... green E. Yellow ... red

A

Which of these phosphorylates ADP to make ATP?

ATP Synthase

C4 plants occur more commonly in desert conditions because _____. A. the stomata open at night and close in the day B. they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed C. they store carbon by incorporating CO2 into organic acids that are later catabolized D. they produce water as a product of their photosynthetic pathways E. they produce carbon dioxide internally via photorespiration

B

Can you tell from these absorption spectra whether red light is effective in driving photosynthesis? A. These absorption spectra indicate that green and yellow wavelengths of light are much more effective than red light. B. One cannot tell from this graph, but because chlorophyll a does absorb red light, we can predict that it would be effective in driving photosynthesis. C. Because the absorption spectra of the pigments are highest in the purple/blue wavelengths, we can assume that red light is not effective.

B

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. A. stomata B. cytoplasm C. grana D. stroma E. thylakoids

B

In the electromagnetic spectrum, the type of radiation that we call visible light occurs between _____. A. infrared radiation and radio waves B. ultraviolet radiation and infrared radiation C. infrared radiation and microwaves D. X-rays and ultraviolet radiation E. radio waves and microwaves

B

Plants are photoautotrophs. What does this mean? A. They are the primary consumers of the biosphere. B. They use light energy to drive the synthesis of organic molecules from inorganic materials. C. They are attracted to light. D. They generate oxygen. E. They synthesize their own food from inorganic materials.

B

Select the correct statement about the Calvin cycle. A. The basic function of the Calvin cycle is the conversion of solar energy to chemical energy. B. The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP. C. The Calvin cycle takes place primarily in the dark.

B

Select the most accurate statement describing the basic function of the light reactions of photosynthesis. A. The basic function of the light reactions of photosynthesis is the production of glucose. B. The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy. C. The basic function of the light reactions of photosynthesis is the trapping of light energy.

B

The light reactions of photosynthesis supply the Calvin cycle with A. sugar and O2. B. ATP and NADPH. C. H2O and NADPH. D. light energy. E. CO2 and ATP.

B

True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain. A. True B. False

B

True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane. A. True B. False

B

Which of the following does not occur during the Calvin cycle? A. regeneration of the CO2 acceptor B. release of oxygen C. oxidation of NADPH D. consumption of ATP E. carbon fixation

B

Which of the following particles can pass through the ATP synthase channel? A. Inorganic phosphate B. Protons C. ATP D. ADP

B

In C3 plants the conservation of water promotes _____. A. photorespiration B. the opening of stomata C. photosynthesis D. the light reactions E. a shift to C4 photosynthesis

A

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? A. 3 B. 1 C. 4 D. 5 E. 2

A

Select the correct molecule that is the main product of the Calvin cycle. A. G3P B. Glucose C. NADPH

A

According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis? A. Proton gradient B. Temperature gradient C. Electrons D. Osmotic gradient

A

After 3-PGA is phosphorylated, it is reduced by _____. A. NADPH B. ADP C. CO2 D. NADP+ E. ATP

A

An action spectrum plots the rate of photosynthesis at various wavelengths of visible light, and it shows that blue light with a wavelength of about 490 nm is effective in driving photosynthesis. Based on this information and the absorption spectra shown at left, what role may chlorophyll b and carotenoids play in photosynthesis? A. These pigments are able to absorb more wavelengths of light (and thus more energy) than chlorophyll a alone can absorb. As part of light-harvesting complexes in photosystems, they broaden the range of light that can be used in the light reactions. B. These pigments probably play only a photoprotective role (absorbing excess light energy that could damage chlorophyll a) and a role in producing the colors of fall foliage. C. Because chlorophyll a is found in the reaction-center complexes of both photosystems II and I, we can assume that these other pigments play no role in photosynthesis.

A

Approximately what wavelength of light is best absorbed by chlorophyll a, the pigment that participates directly in the light reactions? A. 435 nm B. 525 nm C. 680 nm D. One cannot tell from this graph.

A

Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5‎ . The solution is then adjusted to pH 8‎ . Which of the following conclusions can be drawn from these experimental conditions? A. ATP will not be produced because there is no ADP and inorganic phosphate in the solution. B. ATP will be produced because the proton gradient favors proton movement through the ATP synthase channels. C. The change in the solution's pH results in a gradient across the chloroplast membranes such that there is a lower concentration of protons inside the vesicles and a higher concentration outside. D. Protons will not diffuse toward the outside of the vesicles.

A

If only chlorophyll a were involved in the light reactions, would blue light (wavelength about 490 nm) be effective in driving photosynthesis? A. The graph indicates that chlorophyll a absorbs very little blue light, so we can predict that blue light would not be effective. B. The peak absorption for chlorophyll b is close to this wavelength, so we can predict that blue light would be effective. C. One cannot tell from this graph.

A

Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis? A. The light-dependent reactions produce carbon dioxide, which is then used by the light-independent reactions. B. The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions. C. The light-dependent reactions pass electrons through an electron transport chain to the light-independent reactions. D. The light-independent reactions release energy, and the light-dependent reactions require energy.

B

Which process produces oxygen? A. Cellular respiration B. Photosynthesis

B

Which wavelength of light is best absorbed by chlorophyll b? A. 400 nm B. 455 nm C. 540 nm D. 645 nm E. One cannot tell from this graph.

B

Why are plants classified as producers? A. Plants are classified as producers because they are at the bottom of the food chain. B. Plants are classified as producers because they fix inorganic carbon into organic molecules. C. Plants are classified as producers because they produce oxygen.

B

In mechanism, photophosphorylation is most similar to A. reduction of NADP+. B. carbon fixation. C. oxidative phosphorylation in cellular respiration. D. substrate-level phosphorylation in glycolysis. E. the Calvin cycle.

C

Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle. A. reduced...reduced B. consumed...consumed C. oxidized...reduced D. reduced...oxidized E. consumed...reduced

C

What is the basic role of CO2 in photosynthesis? A. CO2 is a source of electrons in the formation of organic molecules. B. CO2 is taken in by plants as a form of inverse respiration, in which carbon dioxide is "breathed in" and oxygen is "breathed out." C. CO2 is fixed or incorporated into organic molecules.

C

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. A. fixing carbon B. removing them from NADPH C. splitting water D. oxidizing glucose E. breaking down ATP

C

Which of the following is a product of the light reactions of photosynthesis? A. water and CO2 B. high-energy photons C. oxygen, ATP, and NADPH D. NADP+ and RuBP E. glyceraldehyde-3-phosphate

C

Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose? A. Carbon fixation B. Production of G3P C. Regneration of RuBP D. Production of 3-phosphoglycerate

C

Which process is most directly driven by light energy? A. ATP synthesis B. reduction of NADP+ molecules C. removal of electrons from chlorophyll molecules D. creation of a pH gradient by pumping protons across the thylakoid membrane E. carbon fixation in the stroma

C

C4 plants differ from C3 and CAM plants in that C4 plants _____. A. open their stomata only at night B. are better adapted to wet conditions C. use malic acid to transfer carbon dioxide to the Calvin cycle D. transfer fixed carbon dioxide to cells in which the Calvin cycle occurs E. use PEP carboxylase to fix carbon dioxide

D

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? A. 8 B. 10 C. 2 D. 6 E. 4

D

The overall function of the Calvin cycle is _____. A. capturing sunlight B. producing carbon dioxide C. oxidizing glucose D. making sugar E. splitting water

D

The photosynthetic membranes are found in the _____ in plant cells. A. mitochondria B. nucleus C. Golgi apparatus D. chloroplasts E. endoplasmic reticulum

D

Which of the following molecules is the primary product of photosystem I? A. Carbon dioxide B. ATP C. Oxygen D. NADPH

D

Which of the following products of the light reactions of photosynthesis is consumed during the Calvin cycle? A. oxygen B. water C. ADP + Pi D. NADPH E. sugar

D

Which of the following sequences correctly represents the flow of electrons during photosynthesis? A. NADPH → O2 → CO2 B. H2O → photosystem I → photosystem II C. NADPH → electron transport chain → O2 D. H2O → NADPH → Calvin cycle E. NADPH → chlorophyll → Calvin cycle

D

Which of the following statements is a correct distinction between autotrophs and heterotrophs? A. Only heterotrophs have mitochondria. B. Only heterotrophs require chemical compounds from the environment. C. Only heterotrophs require oxygen. D. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. E. Cellular respiration is unique to heterotrophs.

D

You obtain the pigments called carotenoids in your diet when you eat carrots. Why do carotenoids appear yellow and orange? A. They absorb yellow and orange wavelengths best. B. Their line on this absorption spectrum is colored orange. C. One cannot tell from this graph. D. They absorb blue/green light and reflect yellow and red wavelengths of light.

D

Carbon fixation involves the addition of carbon dioxide to _____. A. G3P B. 3-PGA C. Rubisco D. NADPH E. RuBP

E

How is photosynthesis similar in C4 plants and CAM plants? A. In both cases, thylakoids are not involved in photosynthesis. B. Both types of plants make sugar without the Calvin cycle. C. Both types of plants make most of their sugar in the dark. D. In both cases, only photosystem I is used. E. In both cases, rubisco is not used to fix carbon initially.

E

The light reactions of photosynthesis use _____ and produce _____. A. carbon dioxide ... sugar B. carbon dioxide ... oxygen C. NADPH ... NADP+ D. NADPH ... oxygen E. water ... NADPH

E