BIOL Exam II: Chapter 10
The net energy outcome of cyclic photophosphorylation is a. ATP. b. ATP and NADH. c. NADPH. d. ATP and NADPH. e. sugar.
a. ATP.
Why is the absorption spectrum of chlorophyll a not identical to the action spectrum of photosynthesis? a. Accessory pigments contribute energy to drive photosynthesis. b. Chlorophyll a absorbs both red and blue light. c. Chlorophyll a reflects green light. d. Different wavelengths of light have different energies. e. Chlorophyll a can be activated by absorbing a photon of light.
a. Accessory pigments contribute energy to drive photosynthesis.
Photosynthesis and respiration are linked through the a. Calvin cycle. b. citric acid cycle. c. enzyme rubisco. d. need for light. e. a, b, and c
a. Calvin cycle.
Which of the following statements concerning the Calvin cycle is false? a. Light energy is not required for the cycle to proceed. b. CO2 is assimilated into sugars. c. RuBP is regenerated. d. It uses energy stored in ATP and NADPH + H+. e. All of the above are false.
a. Light energy is not required for the cycle to proceed.
Which of the following statements regarding photorespiration is true? a. Photorespiration is a metabolically expensive pathway. b. Photorespiration is avoided when CO2 levels are low. c. Photorespiration increases the overall CO2 that is converted to carbohydrates. d. Photorespiration increases by 75 percent the net carbon that is fixed. e. Photorespiration is most common in C4 plants.
a. Photorespiration is a metabolically expensive pathway.
Which of the following statements concerning rubisco is true? a. Rubisco is a carboxylase. b. Rubisco preferentially binds to O2 over CO2. c. Rubisco is absent from C4 and CAM plants. d. Rubisco catalyzes the splitting in water to release O2. e. Rubisco is more allosterically regulated by CO2.
a. Rubisco is a carboxylase.
The wavelength of X rays is shorter than the wave length of infrared rays. Which of the following is true? a. X rays have more energy per photon than infrared rays have. b. X rays have a smaller value for Planck's constant than infrared waves have. c. X rays have a different absorption spectrum than infrared waves have. d. X rays and infrared waves have the same frequency. e. Infrared waves are in the ground state, whereas X rays are in the excited state.
a. X rays have more energy per photon than infrared rays have.
As atmospheric CO2 rises globally, it is known there will be a. an increase in photosynthetic rate. b. an increase in temperature. c. an increase in rainfall. d. a decrease in temperature. e. a decrease in rainfall.
a. an increase in photosynthetic rate.
In bright light, the pH of the thylakoid space a. can become more acidic. b. can become more alkaline. c. stays the same; the pH of the thylakoid space never changes. d. can become neutral. e. None of the above
a. can become more acidic
The enzyme PEP carboxylase a. can trap CO2 even at relatively low CO2 concentrations. b. catalyzes the synthesis of RuBP. c. catalyzes the synthesis of 3PG. d. is found in the chloroplasts of bundle sheath cells. e. couples the synthesis of ATP to the diffusion of protons.
a. can trap CO2 even at relatively low CO2 concentrations.
Plants are green because a. chlorophylls absorb blue and orange-red wavelengths of light and reflect green light. b. chloroplasts transmit green light. c. energized chlorophyll a emits green light. d. plants do not possess green pigment. e. chlorophylls absorb green light.
a. chlorophylls absorb blue and orange-red wavelengths of light and reflect green light.
The enzyme rubisco is found in a. chloroplasts. b. mitochondria. c. the cytoplasm. d. the nucleus. e. yeast.
a. chloroplasts.
In both photosynthesis and respiration, protons are pumped across a membrane during a. electron transport. b. photolysis. c. CO2 fixation. d. reduction of O2. e. glycolysis.
a. electron transport.
When RuBP reacts with O2, a. it cannot react with CO2. b. carbohydrate production increases. c. plant growth is stimulated. d. net carbon fixation increases by 25 percent. e. two carbon molecules combine to form the four-carbon phosphoglycolate.
a. it cannot react with CO2.
Cyclic and noncyclic electron flow are used in plants to a. meet the ATP demands of the Calvin cycle. b. produce excess NADPH + H+. c. synthesize proportional amounts of ATP and NADPH + H+ in the chloroplast. d. consume the products of the Calvin cycle. e. produce O2 for the atmosphere.
a. meet the ATP demands of the Calvin cycle.
Photorespiration takes place in a. mitochondria, chloroplasts and peroxisomes b. chloroplasts and mitochondria c. C4 plants only. d. the microbodies. e. the cytoplasm and peroxisomes
a. mitochondria, chloroplasts and peroxisomes
The energy to hydrolyze water comes from a. oxidized chlorophyll. b. reduced chlorophyll. c. the proton gradient. d. ATP. e. NADPH + H+.
a. oxidized chlorophyll.
The light energy absorbed by the P680 reaction center a. oxidizes water. b. removes a phosphate from ATP to form ADP. c. fixes CO2 to form sugars. d. is used to form rubisco. e. is reflected and causes plants to appear green.
a. oxidizes water.
The Z scheme is a. the characteristic path of electrons when they are bounced out of the pigments of the reaction center. b. another name for the splitting of water. c. the addition of CO2 to RuBP to form a six-carbon sugar. d. the passing of high-energy electrons through ATP synthase. e. the wavelengths of light absorbed by a specific molecule.
a. the characteristic path of electrons when they are bounced out of the pigments of the reaction center.
When a photon is absorbed by chlorophyll, a. the chlorophyll becomes "excited," or energized. b. a greater number of light wavelengths can be absorbed. c. ATP is split into ADP, phosphate, and energy. d. hydrogen ions are released. e. the chlorophyll molecules fluoresce.
a. the chlorophyll becomes "excited," or energized.
The enzyme ATP synthase couples the synthesis of ATP to a. the diffusion of protons. b. the reduction of NADP+. c. the excitation of chlorophyll. d. the reduction of chlorophyll. e. CO2 fixation.
a. the diffusion of protons.
Photorespiration reduces the net carbon fixed by the Calvin cycle by _______ percent. a. 70 b. 25 c. 2.1 d. 0.21 e. 0.02
b. 25
Which of the following is the revised, balanced equation for the generation of sugar from sunlight, water, and CO2? a. 6 CO2 + 6 H2O → C6H12O6 + O2 b. 6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O c. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 d. 12 CO2 + 12 H2O → 2 C6H12O6 + 2 O2 e. None of the above
b. 6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O
In cyclic electron transport, a. oxygen gas is released. b. ATP is formed. c. water donates electrons and protons. d. NADPH forms. e. CO2 reacts with RuBP.
b. ATP is formed.
Which statement about light is true? a. An absorption spectrum is a plot of biological effectiveness versus wavelength. b. An absorption spectrum may be a good means of identifying a pigment. c. Light need not be absorbed to produce a biological effect. d. A given kind of molecule can occupy any energy level. e. A pigment loses energy as it absorbs a photon.
b. An absorption spectrum may be a good means of identifying a pigment.
Which of the following occurs during the light-independent reactions of photosynthesis? a. Water is converted into hydrogen and water. b. CO2 is converted into sugars. c. Chlorophyll acts as an enzyme. d. Nothing occurs; the plant rests in the dark. e. None of the above
b. CO2 is converted into sugars.
CAM plants differ from C4 plants in that a. photosynthesis can occur at night in CAM plants. b. CO2 is stored in CAM plants as malic acid. c. the stomata of CAM plants close during periods that favor photorespiration. d. CAM plants use PEP carboxylase to fix CO2. e. the Calvin cycle is only found in C4 and C3 plants, not in CAM plants.
b. CO2 is stored in CAM plants as malic acid.
During photorespiration, rubisco uses _______ as a substrate. a. CO2 b. O2 c. glyceraldehyde 3-phosphate d. 3-phosphoglycerate e. NADPH
b. O2
Which of the following statements concerning the light reactions of photosynthesis is true? a. Photosystem I cannot operate independently of photosystem II. b. Photosystems I and II are activated by different wavelengths of light. c. Photosystems I and II transfer electrons and create proton equilibrium across the thylakoid membrane. d. Photosystem I is more significant than Photosystem II. e. Oxygen gas is a product of Photosystem I.
b. Photosystems I and II are activated by different wavelengths of light.
In noncyclic photophosphorylation, the chlorophyll in photosystem I returns to its reduced state by a. water. b. accepting electrons from the transport chain of photosystem II. c. two photons of light. d. NADPH. e. ATP.
b. accepting electrons from the transport chain of photosystem II.
The fixation of CO2 by PEP carboxylase functions to a. concentrate O2 for use in photosynthetic cells. b. allow plants to close stomata without the occurrence of photorespiration. c. allow plants to photosynthesize in the dark. d. reduce water loss by the plant. e. All of the above
b. allow plants to close stomata without the occurrence of photorespiration.
After the removal of carbon, the oxygen in CO2 ends up a. as atmospheric oxygen. b. attached to carbon and hydrogen to form sugar (G3P). c. in the soil. d. attached to hydrogen to form water. e. as rubisco.
b. attached to carbon and hydrogen to form sugar (G3P).
Because of the properties of chlorophyll, plants need adequate _______ light to grow properly. a. green b. blue and red c. infrared d. ultraviolet e. blue and blue-green
b. blue and red
ATP is produced during the light reactions via a. CO2 fixation. b. chemiosmosis. c. reduction of water. d. glycolysis. e. noncyclic electron flow from photosystem I.
b. chemiosmosis.
In cacti, CO2 is stored for use in the Calvin cycle a. in the stems, roots, and leaves. b. during the evening. c. in glucose molecules. d. in the stroma. e. Both a and d
b. during the evening.
The level of atmospheric CO2 has varied considerably over the years. Currently, the level of atmospheric CO2 a. is four times what is was during the time of the dinosaurs. b. favors C4 plants under hot conditions. c. has resulted in maximum CO2 fixation by rubisco. d. is decreasing. e. prevents the occurrence of photorespiration.
b. favors C4 plants under hot conditions.
Compared to long-wavelength photons, short-wavelength photons have a. an insignificant amount of energy. b. more energy. c. energy not available to plant cells. d. a ladder of energy. e. an equal amount of energy.
b. more energy.
Photosynthesis occurs a. in all plant cells. b. only in photosynthetic plant cells. c. only in plant cells lacking mitochondria. d. only in the stroma. e. only in the thylakoid membrane.
b. only in photosynthetic plant cells.
The photosynthetic pigment chlorophyll a absorbs a. infrared light. b. orange-red and blue light. c. X rays. d. gamma rays. e. white light.
b. orange-red and blue light.
When a photon is absorbed by a molecule, the photon a. loses its ability to generate any energy. b. raises the molecule from a ground state of low energy to an excited state. c. affects the molecule in ways that are not clearly understood. d. causes a change in the velocity of the wavelengths. e. None of the above
b. raises the molecule from a ground state of low energy to an excited state.
The NADPH required for the reduction of 3PG to G3P comes from a. the dark reactions. b. the light reactions. c. the synthesis of ATP. d. the Calvin cycle. e. oxidative phosphorylation.
b. the light reactions.
Photorespiration a. results in CO2 fixation. b. uses ATP and NADPH produced in the light reactions. c. generates a proton gradient. d. results in the synthesis of glucose. e. All of the above
b. uses ATP and NADPH produced in the light reactions.
Heterotrophs are dependent on autotrophs for their food supply. Autotrophs can make their own food by a. feeding on bacteria and converting the nutrients into usable energy. b. using light and simple chemicals to make reduced carbon compounds. c. synthesizing it from water and CO2. d. All of the above e. None of the above
b. using light and simple chemicals to make reduced carbon compounds.
In noncyclic photophosphorylation, electrons from _______ replenish chlorophyll molecules that have given up electrons. a. CO2 b. water c. NADPH + H+ d. O2 gas e. None of the above
b. water
When CO2 is added to RuBP, the first stable product synthesized is a. pyruvate. b. ribulose 1,5-bisphosphate. c. 3PG. d. ATP. e. glyceraldehyde 3-phosphate (G3P).
c. 3PG.
Which of the following begins the Calvin cycle that results in the entire pathway being carried out under environmental conditions? a. 3PG is reduced to G3P using ATP and NADPH + H+. b. RuBP is regenerated. c. CO2 and RuBP join forming 3PG. d. G3P is converted into glucose and fructose. e. Any of the above; as a cycle, it can start at any point.
c. CO2 and RuBP join forming 3PG.
What is the difference between chlorophyll a and chlorophyll b? a. Chlorophyll a has a complex ring structure, whereas chlorophyll b has a linear structure. b. Chlorophyll a has a magnesium atom at its center, whereas chlorophyll b has a phosphate group at its center. c. Chlorophyll a has a methyl group, whereas chlorophyll b has an aldehyde group. d. A hydrocarbon tail is found only in chlorophyll a. e. Chlorophyll a fluoresces, whereas chlorophyll b passes the absorbed energy to another molecule.
c. Chlorophyll a has a methyl group, whereas chlorophyll b has an aldehyde group.
How do red and blue light differ from one another? a. They differ in intensity. b. They have a different number of photons in each quantum. c. Their wavelengths are different. d. They differ in duration. e. Red is radiant, whereas blue is electromagnetic.
c. Their wavelengths are different.
The chemiosmotic hypothesis states that the energy for the production of ATP comes from a. the transfer of phosphate from intermediate compounds. b. the reduction of NADP. c. a proton gradient set up across the thylakoid membrane. d. the oxidation of CO2. e. Both a and b
c. a proton gradient set up across the thylakoid membrane.
In C4 plants, the function of the four-carbon compound that is synthesized in the mesophyll cells is to a. reduce NADP+. b. combine with CO2 to produce glucose. c. carry CO2 to the bundle sheath cells. d. drive the synthesis of ATP. e. close the stomata.
c. carry CO2 to the bundle sheath cells.
The precise moment when light energy is captured in chemical energy is the point at which a. light shines on chlorophyll. b. water is hydrolyzed. c. chlorophyll is oxidized. d. chlorophyll is reduced. e. the CO2 from air is captured in a sugar.
c. chlorophyll is oxidized.
The main function of photosynthesis is the a. consumption of CO2. b. production of ATP. c. conversion of light energy to chemical energy. d. production of starch. e. production of O2.
c. conversion of light energy to chemical energy.
The NADPH required for CO2 fixation is formed a. by the reduction of O2. b. by the hydrolysis of ATP. c. during the light reactions. d. in C4 plants only. e. in the mitochondria.
c. during the light reactions.
In C4 plants, CO2 is first fixed into a compound called a. pyruvate. b. glucose. c. oxaloacetate. d. ribulose bisphosphate. e. 3-phosphoglycerate.
c. oxaloacetate.
In cyclic photophosphorylation, chlorophyll is reduced by a. NADPH. b. a chemiosmotic mechanism. c. plastoquinone. d. ATP. e. hydrogen ions liberated by the splitting of a water molecule.
c. plastoquinone.
In noncyclic photophosphorylation, water is used for the a. hydrolysis of ATP. b. excitation of chlorophyll. c. reduction of chlorophyll. d. oxidation of NADPH. e. synthesis of chlorophyll.
c. reduction of chlorophyll.
When a suspension of algae is incubated in a flask in the presence of light and CO2 and then transferred to the dark, the reduction of 3-phosphoglycerate to glyceraldehyde 3-phosphate is blocked. This reaction stops when the algae are placed in the dark because a. the reaction requires CO2. b. the reaction is exergonic. c. the reaction requires ATP and NADPH + H+. d. the reaction requires O2. e. chlorophyll is not synthesized in the dark.
c. the reaction requires ATP and NADPH + H+.
Plants give off O2 because a. O2 results from the incorporation of CO2 into sugars. b. they do not respire; they photosynthesize. c. water is the initial electron donor, leaving O2 as a photosynthetic by-product. d. electrons moving down the electron chain bind to water, releasing O2. e. O2 is synthesized in the Calvin cycle.
c. water is the initial electron donor, leaving O2 as a photosynthetic by-product.
The O2 gas produced during photosynthesis is derived from a. CO2. b. glucose. c. water. d. CO. e. bicarbonate ions.
c. water.
How many moles of CO2 must enter the Calvin-Benson cycle for the synthesis of one mole of glucose? a. 1 b. 2 c. 3 d. 6 e. 12
d. 6
Activities such as amino acid synthesis and active transport in plant cells are powered by a. the light-dependent and light-independent reactions of photosynthesis. b. ATP from the light reactions of photosynthesis. c. ATP from fermentation. d. ATP from glycolysis and cellular respiration. e. All of the above
d. ATP from glycolysis and cellular respiration.
Which of the following best represent the components that are necessary for photosynthesis to take place? a. Mitochondria, accessory pigments, visible light, water, and CO2 b. Chloroplasts, accessory pigments, visible light, water, and CO2 c. Mitochondria, chlorophyll, visible light, water, and O2 d. Chloroplasts, chlorophyll, visible light, water, and CO2 e. Chlorophyll, accessory pigments, visible light, water, and O2
d. Chloroplasts, chlorophyll, visible light, water, and CO2
Which statement about chlorophylls is not true? a. Chlorophylls absorb light near both ends of the visible spectrum. b. Chlorophylls can accept energy from other pigments, such as carotenoids. c. Excited chlorophyll can either reduce another substance or release light energy. d. Excited chlorophyll cannot be an oxidizing agent. e. Chlorophylls contain magnesium.
d. Excited chlorophyll cannot be an oxidizing agent.
The Calvin cycle results in the production of a. glucose. b. starch. c. rubisco. d. G3P. e. ATP.
d. G3P.
Which of the following statements about photosynthesis is false? a. The water for photosynthesis in land plants comes primarily from the soil. b. CO2 is taken in, and water and O2 are released through stomata. c. Light is necessary for the production of O2 and carbohydrates. d. Photosynthesis is the reverse of cellular respiration. e. All the O2 gas produced during photosynthesis comes from water.
d. Photosynthesis is the reverse of cellular respiration.
Accessory pigments a. play no role in photosynthesis. b. transfer energy from chlorophyll to the electron transport chain. c. absorb only the red wavelengths. d. allow plants to absorb visible light of intermediate wavelengths. e. transfer electrons to NADP.
d. allow plants to absorb visible light of intermediate wavelengths.
Photosynthesis takes place in plants only in the light. Respiration takes place a. in the dark only. b. in the light only. c. in all organisms except plants. d. both with and without light. e. None of the above
d. both with and without light.
The main photosynthetic pigments in plants are _______ and _______. a. chlorophyll s; chlorophyll a b. chlorophyll x; chlorophyll y c. retinal pigment; accessory pigment d. chlorophyll a; chlorophyll b e. None of the above
d. chlorophyll a; chlorophyll b
The Calvin-Benson cycle uses more ATP than NADPH + H+. The needed ATP comes from a. the splitting of water. b. the reduction of oxygen. c. the oxidation of glucose. d. cyclic P700. e. noncyclic electronic transport.
d. cyclic P700.
Free energy is released in cyclic photophosphorylation a. by the formation of ATP. b. during the excitation of chlorophyll. c. during the fluorescence of chlorophyll. d. during each of the redox reactions of the electron transport chain. e. when electrons are transferred from photosystem I to photosystem II.
d. during each of the redox reactions of the electron transport chain.
The first phase of photosynthesis, a series of reactions that requires the absorption of photons to form ATP and NADPH, is referred to as the _______ phase. a. reduction b. dark reactions c. carbon fixation d. light reactions (or photophosphorylation) e. None of the above
d. light reactions (or photophosphorylation)
The Intergovernmental Panel of Climate Change, sponsored by the United Nations, may be able to impact global climate change by a. wavelengths of lights that are not part of the absorption spectrum. b. light energy that is not absorbed. c. inefficiency of light reactions that convert light to chemical energy. d. reducing carbon dioxide emissions. e. inefficiency chemical energy storage of photosynthetic products.
d. reducing carbon dioxide emissions.
When white light strikes a blue pigment, blue light is a. reduced. b. absorbed. c. converted to chemical energy. d. scattered or transmitted. e. used to synthesize ATP.
d. scattered or transmitted.
During cyclic photophosphorylation, the energy to produce ATP is provided by a. heat. b. NADPH. c. ground-state chlorophyll. d. the redox reactions of the electron transport chain. e. the Calvin-Benson cycle.
d. the redox reactions of the electron transport chain.
A range of energy that cannot be seen by human eyes but has slightly more energy per photon than visible light is known as _______ radiation. a. adaptive b. solar c. gamma d. ultraviolet e. None of the above
d. ultraviolet
Photosynthesis is the process that uses light energy to extract hydrogen atoms from a. glucose. b. chlorophyll. c. CO2. d. water. e. None of the above
d. water.
During CO2 fixation, CO2 combines with a. NADPH. b. 3PG. c. G3P. d. water. e. 1,5-ribulose bisphosphate.
e. 1,5-ribulose bisphosphate.
Photophosphorylation provides the Calvin-Benson cycle with a. protons and electrons. b. CO2 and glucose. c. water and photons. d. light and chlorophyll. e. ATP and NADPH.
e. ATP and NADPH.
Chlorophyll is suited for the capture of light energy because a. certain wavelengths of light raise it to an excited state. b. in its excited state it gives off electrons. c. its structure allows it to attach to thylakoid membranes. d. it can transfer absorbed energy to another molecule. e. All of the above
e. All of the above
Cyclic electron transport a. occurs when the ratio of NADPH + H+ to NADP+ in the chloroplasts of some organisms is high. b. is a series of redox reactions. c. stores its released energy as a proton gradient. d. is completed when the electron returns to P700+. e. All of the above
e. All of the above
Global climate change may a. increase photosynthetic rate. b. increase plant growth. c. change temperature throughout the globe. d. necessitate a change in the crops grown. e. All of the above
e. All of the above
How is the Calvin cycle connected to the light reactions? a. The light-induced pH changes activate rubisco. b. The light-induced electron flow changes the shape of four Calvin-cycle enzymes. c. The Calvin cycle needs the ATP produced in the light reactions. d. None of the above e. All of the above
e. All of the above
The Calvin cycle uses _______ to produce glucose. a. CO2 b. ATP c. NADPH d. rubisco e. All of the above
e. All of the above
When a photon interacts with molecules such as those within chloroplasts, the photons may a. bounce off the molecules, having no effect. b. pass through the molecules, having no effect. c. be absorbed by the molecules. d. Both a and c e. All of the above
e. All of the above
Which of the following biological groups is dependent on photosynthesis for its survival? a. Vertebrates b. Mammalia c. Fishes d. Plants e. All of the above
e. All of the above
How does rubisco "decide" whether to act as an oxygenase or a carboxylase? a. Rubisco has 10 times more affinity for O2 than CO2; therefore, it favors O2 fixation. b. If O2 is relatively abundant, rubisco acts as a carboxylase. c. If O2 predominates, rubisco fixes it and the Calvin-Benson cycle occurs. d. Photorespiration is more likely at low temperatures. e. As the ratio of CO2 to O2 falls in the leaf, the reaction of rubisco with O2 is favored, and photorespiration proceeds.
e. As the ratio of CO2 to O2 falls in the leaf, the reaction of rubisco with O2 is favored, and photorespiration proceeds.
Which of the following scientific tools "cracked" the Calvin-Benson cycle? a. Radioisotopes b. Paper chromatography c. Crystallography d. Centrifugation and electron microscopy e. Both a and b
e. Both a and b
A suspension of algae is incubated in a flask in the presence of both light and CO2. When it is transferred to the dark, the reduction of 3-phosphoglycerate to glyceraldehyde 3-phosphate is blocked, and the concentration of ribulose bisphosphate (RuBP) declines. Why does the RuBP concentration decline? a. Ribulose bisphosphate is synthesized from glyceraldehyde 3-phosphate. b. Glyceraldehyde 3-phosphate is converted to glucose. c. Ribulose bisphosphate is used to synthesize 3-phosphoglycerate. d. Both a and b e. Both a and c
e. Both a and c
Plants classified as CAM store CO2 a. by making oxaloacetate. b. by making PEP carboxylase. c. in malic acid. d. in crassulacean acid. e. Both a and c
e. Both a and c
Which of the following statements regarding the relationship between photosynthesis and cellular respiration in plants is true? a. Photosynthesis occurs in specialized photosynthetic cells. b. Cellular respiration occurs in specialized respiratory cells. c. Cellular respiration and photosynthesis can occur in the same cell. d. Photosynthesis is limited to specialized plant cells and cellular respiration does not occur in plant cells. e. Both a and c
e. Both a and c
If global climate change continues and CO2 levels continue to rise, a. C4 plants will be favored. b. C3 plants will have a comparative advantage. c. More rice and wheat should be grown. d. Photorespiration will increase. e. Both b and c
e. Both b and c
The energy difference between an electron excited by a photon and the electron in its ground state is _______ of the photon. a. less than the energy b. greater than the energy c. equal to the energy d. related to the wavelength e. Both c and d
e. Both c and d
The energy source for the synthesis of carbohydrates in the Calvin cycle is a. ATP only. b. photons. c. energized chlorophyll a. d. NADPH + H+. e. NADPH and ATP.
e. NADPH and ATP.
A molecule that has an absorption spectrum showing maximum absorption within the wavelengths of visible light is a. a reducing agent. b. a quantum. c. a photon. d. electromagnetic radiation. e. a pigment.
e. a pigment.
Photosynthesis and respiration have which of the following in common? a. In eukaryotes, both processes reside in specialized organelles. b. ATP synthesis in both processes relies on the chemiosmotic mechanism. c. Both use electron transport. d. Both require light. e. a, b, and c
e. a, b, and c
A graph that plots the rate at which CO2 is converted to glucose versus the wavelength of light illuminating a leaf is called a. a Planck equation. b. an absorption spectrum. c. enzyme kinetics. d. an electromagnetic spectrum. e. an action spectrum.
e. an action spectrum.
In C4 plants, starch grains are found in the chloroplasts of a. the thylakoids. b. mesophyll cells. c. the intracellular space. d. the stroma. e. bundle sheath cells.
e. bundle sheath cells.
In plants, the reactions of glycolysis occur a. in C3 plants only. b. in the mitochondria. c. in the chloroplasts. d. only in the presence of light. e. in the cytosol.
e. in the cytosol.
In noncyclic photosynthetic electron transport, water is used to a. excite chlorophyll. b. hydrolyze ATP. c. reduce Pi. d. oxidize NADPH. e. reduce chlorophyll.
e. reduce chlorophyll.
Photosynthesis a. uses 100 percent of the sunlight that reaches Earth. b. is a very efficient biochemical pathway. c. utilizes all wavelengths of light. d. converts 90 percent of light energy to chemical energy. e. utilizes only a small portion of the energy of sunlight.
e. utilizes only a small portion of the energy of sunlight.