AP Bio Chapter 10

What assumptions did Engelmann make in order to conclude that red and violet-blue light were more effective than green light in driving photosynthesis? *The alga absorbed the same number of photons at each wavelength (color) * The distribution of chloroplasts within each algal cell was approximately the same. * The number of bacteria clustered at each wavelength (color) was approximately proportional to the amount of oxygen being produced by that portion of the alga. * Every photon absorbed by the alga was used to drive oxygen production by the alga.

* The distribution of chloroplasts within each algal cell was approximately the same. * The number of bacteria clustered at each wavelength (color) was approximately proportional to the amount of oxygen being produced by that portion of the alga.

The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce _______ to _______.

CO₂, G3P

In the light reactions, light energy is used to oxidize _______ to ______.

H₂O, O₂

The Calvin cycle oxidizes the light-reactions product ______ to ______.

NADPH, NADP⁺

The electrons derived from this oxidation reaction in the light reactions are used to reduce ______ to _____.

NADP⁺, NADPH

NADP+

Nicotinamide adenine dinucleotide phosphate, an electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions.

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

True

reaction-center complex

a complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. located centrally in a photosystem, this complex triggers the light reactions of photosynthesis. excited by light energy, the pair of chlorophylls donates an electron to the primary electron acceptor, which passes an electron to an electron transport chain.

light-harvesting complex

a complex of proteins associated with pigment molecules (including chlorophyll a, chlorophyll b, and carotenoids) that captures light energy and transfers it to reaction-center pigments in a photosystem

thylakoid

a flattened, membranous sac inside a chloroplast. thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular; used to convert light energy to chemical energy

action spectrum

a graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process

chlorophyll

a green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. chlorophyll a participates directly in the light reactions, which convert solar energy to chemical energy.

photosystem I

a light-capturing unit in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P700 chlorophyll a at its reaction center

photosystem

a light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. there are two types of photosystems, I and II; they absorb light best at different wavelengths.

photorespiration

a metabolic pathway that consumes oxygen and ATP, releases carbon dioxide, and decreases photosynthetic output. photorespiration generally occurs on hot, dry, bright days, when stomata close and the O2/CO2 ratio in the leaf increases, favoring the binding of O2 rather than CO2 by rubisco.

stoma

a microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant

chlorophyll a

a photosynthetic pigment that participates directly in the light reactions, which convert solar energy to chemical energy.

C4 plant

a plant in which the Calvin cycle is preceded by reactions that incorporate CO2 into a four-carbon compound, the end product of which supplies CO2 for the Calvin cycle.

CAM plant

a plant that uses crassulacean acid metabolism, an adaptation for photosyntehsis in arid conditions. in this process, carbon dioxide entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed.

C3 plant

a plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate

photon

a quantum, or discrete quantity, or light energy that behaves as it it were a particle.

linear electron flow

a route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP, NADPH, and O2. the net electron flow is from H2O to NADP+

cyclic electron flow

a route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or O2

glyceraldehyde 3-phosphate (G3P)

a three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis

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) 435 nm

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

a) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO₂ and other nutrients that are inorganic.

Can you tell from these absorption spectra whether red light is effective in driving photosynthesis? a) 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. b) These absorption spectra indicate that green and yellow wavelengths of light are much more effective than red light. c) Because the absorption spectra of the pigments are highest in the purple/blue wavelengths, we can assume that red light is not effective.

a) 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.

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) The graph indicates that chlorophyll a absorbs very little blue light, so we can predict that blue light would not be effective.

Which set of reactions uses H₂O and produces O₂? a) The light-dependent reactions. b) The light-independent reactions.

a) The light-dependent reactions.

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

a) They absorb blue/green light and reflect yellow and red wavelengths of light.

The most important role of pigments in photosynthesis is to _____. a) capture light energy b) screen out harmful ultraviolet rays c) store energy d) catalyze the hydrolysis of water e) catalyze the synthesis of ATP

a) capture light energy

Which of the following is cycled in the cyclic variation of the light reactions? a) electrons b) ATP c) NADPH d) ribulose bisphosphate e) protons

a) electrons

In mechanism, photophosphorylation is most similar to a) oxidative phosphorylation in cellular respiration. b) substrate-level phosphorylation in glycolysis. c) carbon fixation. d) reduction of NADP⁺ e) the Calvin cycle.

a) oxidative phosphorylation in cellular respiration.

Which process produces oxygen? a) photosynthesis b) cellular respiration

a) photosynthesis

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by ______. a) splitting water b) breaking down ATP c) fixing carbon d) removing them from NADPH e) oxidizing glucose

a) splitting water

Rubisco is _____. a) the enzyme in plants that first captures CO2 to begin the Calvin cycle b) the enzyme responsible for splitting H2O to produce O2 in photosynthesis c) the enzyme that forms a 4-carbon compound in CAM photosynthesis d) the first stable intermediate in C4 photosynthesis e) the 5-carbon sugar molecule that reacts with CO2 to begin the Calvin cycle

a) the enzyme in plants that first captures CO2 to begin the Calvin cycle

Chlorophyll molecules are in which part of the chloroplast? a) thylakoid membranes b) stroma c) stomata d) plasma membrane e) thylakoid lumen

a) thylakoid membranes

Both mitochondria and chloroplasts _____. a) use chemiosmosis to produce ATP b) obtain electrons from water c) reduce NAD+, forming NADP d) release oxygen as a by-product e) are surrounded by a single membrane

a) use chemiosmosis to produce ATP

chlorophyll b

an accessory photosynthetic pigment that transfers energy to chlorophyll a

carotenoid

an accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. by absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis

crassulacean acid metabolism (CAM)

an adaptation for photosynthesis in arid conditions, first discovered in the family Crassulaceae. In this process, a plant takes up CO2 and incorporates it into a variety of organic acids at night; during the day, CO2 is released from organic acids for use in the Calvin cycle.

PEP carboxylase

an enzyme that adds CO2 to phosphoenopyruvate (PEP) to form oxaloacetate in mesophyll cells of C4 plants. it acts prior to photosynthesis

spectrophotometer

an instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution

heterotroph

an organism that obtains organic food molecules by eating other organisms or substances derived from them

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) 455 nm

The light reactions of photosynthesis supply the Calvin cycle with a) sugar and O₂. b) ATP and NADPH. c) H₂O and NADPH. d) CO₂ and ATP. e) light energy.

b) ATP and NADPH

During photosynthesis in chloroplasts, O2 is produced from _____ via a series of reactions associated with _____. a) CO2 ... photosystem II b) H2O ... photosystem II c) CO2 ... the Calvin cycle d) H2O ... photosystem I e) CO2 ... both photosystem I and the Calvin cycle

b) H2O...photosystem II

How is photosynthesis similar in C4 plants and CAM plants? a) In both cases, thylakoids are not involved in photosynthesis. b) In both cases, rubisco is not used to fix carbon initially. c) In both cases, only photosystem I is used. d) Both types of plants make sugar without the Calvin cycle. e) Both types of plants make most of their sugar in the dark.

b) In both cases, rubisco is not used to fix carbon initially.

Which of the following molecules is the primary product of photosystem I? a) ATP b) NADPH c) Oxygen d) Carbon dioxide

b) NADPH

__________ has a longer wavelength than _________. a) Blue...green b) Red...green c) Yellow...red d) Green...yellow e) Violet...blue

b) Red...green

Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose? a) Production of 3-phosphoglycerate b) Regeneration of RuBP c) Carbon fixation d) Production of G3P

b) Regeneration of RuBP

Carbon fixation involves the addition of carbon dioxide to _______. a) Rubisco b) RuBP c) 3-PGA d) G3P e) NADPH

b) RuBP

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) 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. b) 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. c) 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.

b) 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.

Why are C4 plants more suited to hot climates than C3 plants? a) They do not close their stomata in hot, dry weather. b) Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low. c) They evolved in cold weather but migrated to the tropics, where they were more suitable. d) They suspend photosynthesis in the heat. e) The same cells that bind carbon dioxide perform the Calvin cycle.

b) Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low.

You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark? a) Even though it can't carry out the light reactions, the plant can still produce sugars because the Calvin cycle doesn't require light. b) While it did have access to light, the plant stored energy in the form of sugars or starch, and it was able to derive energy from the stored molecules during your vacation. c) Even though the plant received no visible light, it was able to use the short-wave part of the electromagnetic spectrum (gamma rays and X-rays) to carry out photosynthesis. d) When light energy is not available, plants can derive energy from inorganic molecules. e) None of the listed responses is correct.

b) While it did have access to light, the plant stored energy in the form of sugars or starch, and it was able to derive energy from the stored molecules during your vacation.

In the Calvin cycle, CO2 is combined with _____. a) a 2-carbon compound to form a 3-carbon compound b) a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two 3-carbon compounds c) a 7-carbon compound to form two 4-carbon compounds d) a 5-carbon compound to form a stable 6-carbon compound that can be converted directly to glucose e) two 2-carbon compounds to form a 5-carbon compound

b) a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two 3-carbon compounds

What is the range of wavelengths of light that are absorbed by the pigments in the thylakoid membranes? a) green, which is why plants are green b) blue-violet and red-orange c) the entire spectrum of white light d) the infrared e) the range absorbed by carotenoids

b) blue-violet and red-orange

In photosynthesis, plants use carbon from _____ to make sugar and other organic molecules. a) water b) carbon dioxide c) chlorophyll d) the sun e) soil

b) carbon dioxide

In C₄ and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. a) grana b) cytoplasm c) thylakoids d) stroma e) stomata

b) cytoplasm

Molecular oxygen is produced during _____. a) glycolysis b) noncyclic electron flow during the light reactions c) the Calvin cycle d) cyclic electron flow during the light reactions e) re-energization of electrons by PSI

b) noncyclic electron flow during the light reactions

Photosynthesis is a redox reaction. This means that H₂O is ______ during the light reactions and CO₂ is _______ during the Calvin cycle. a) consumed...reduced b) oxidized...reduced c) consumed...consumed d) reduced...oxidized e) reduced...reduced

b) oxidized...reduced

In C₃ plants the conservation of water promotes _______. a) the opening of stomata b) photorespiration c) a shift to C₄ photosynthesis d) the light reactions

b) photorespiration

Which of the following does not occur during the Calvin cycle? a) consumption of ATP b) release of oxygen c) regeneration of the CO₂ acceptor d) oxidation of NADPH e) carbon fixation

b) release of oxygen

Which process is most directly driven by light energy? a) carbon fixation in the stroma b) removal of electrons from chlorophyll molecules c) ATP synthesis d) creation of a pH gradient by pumping protons across the thylakoid membrane e) reduction of NADP⁺ molecules

b) removal of electrons from chlorophyll molecules

What structure is formed by the reaction center, light-harvesting complexes, and primary electron acceptors that cluster, and is located in the thylakoid membrane? a) the fluorescence center b) the photosystem c) the electron transport chain d) NADP+ reductase e) ATP synthase

b) the photosystem

During photosynthesis in a eukaryotic cell, an electrochemical gradient is formed across the ______. a) chloroplast outer membrane b) thylakoid membrane c) chloroplast inner membrane d) stomata e) cristae

b) thylakoid membrane

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? a) 4 b) 5 c) 3 d) 1 e) 2

c) 3

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? a) 10 b) 2 c) 6 d) 4 e) 8

c) 6

The light reactions of photosynthesis supply the Calvin cycle with a) H2O and NADPH. b) sugar and O2. c) ATP and NADPH. d) light energy. e) CO2 and ATP.

c) ATP and NADPH

Of the following, which occurs during the Calvin cycle? a) Light energy is converted to chemical energy. b) ATP and NADPH are synthesized. c) CO2 is reduced. d) Excited electrons are conveyed from chlorophyll to an electron acceptor. e) Photons are absorbed.

c) CO2 is reduced.

Which of the following groups of organisms contains only heterotrophs? a) Bacteria b) Protozoa c) Fungi d) multicellular algae e) unicellular algae

c) Fungi

Which of the following sequences correctly represents the flow of electrons during photosynthesis? a) NADPH → electron transport chain → O2 b) NADPH → O2 → CO2 c) H2O → NADPH → Calvin cycle d) NADPH → chlorophyll → Calvin cycle e) H2O → photosystem I → photosystem II

c) H2O → NADPH → Calvin cycle

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

c) The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.

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

c) The light-independent reactions turn CO₂, a gas, into usable carbon in the form of sugars.

What is the biological significance of the light-independent reactions of photosynthesis? a) They generate ATP and NADPH. b) They make oxygen. c) They convert carbon dioxide to sugar. d) They convert ATP to sugar.

c) They convert carbon dioxide to sugar.

A photon of which of these colors would carry the most energy? a) green b) yellow c) blue d) orange e) red

c) blue

You could distinguish a granum from a crista because the granum, but not the crista, would _____. a) be inside a mitochondrion b) function in energy transformation c) have photosynthetic pigments d) contain protein but not lipids e) Two of the listed responses are correct.

c) have photosynthetic pigments

The overall function of the Calvin cycle is _____. a) oxidizing glucose b) producing carbon dioxide c) making sugar d) capturing sunlight e) splitting water

c) making sugar

The energy used to produce ATP in the light reactions of photosynthesis comes from _____. a) the oxidation of sugar molecules b) splitting water c) movement of H+ through a membrane d) carbon fixation e) fluorescence

c) movement of H+ through a membrane

In mechanism, photophosphorylation is most similar to a) the Calvin cycle. b) carbon fixation. c) oxidative phosphorylation in cellular respiration. d) substrate-level phosphorylation in glycolysis. e) reduction of NADP+.

c) oxidative phosphorylation in cellular respiration.

Which process is most directly driven by light energy? a) carbon fixation in the stroma b) creation of a pH gradient by pumping protons across the thylakoid membrane c) removal of electrons from chlorophyll molecules d) ATP synthesis e) reduction of NADP+ molecules

c) removal of electrons from chlorophyll molecules

The Calvin cycle occurs in the _____. a) thylakoid membrane b) thylakoid lumen c) stroma d) stomata e) matrix

c) stroma

The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why? a) It is often too cold at night for these reactions to take place. b) Carbon dioxide concentrations decrease at night. c) The Calvin cycle requires products only produced when the photosystems are illuminated. d) Plants usually open their stomata at night. e) At night, no water is available for the Calvin cycle.

c) the Calvin cycle requires products only produced when the photosystems are illuminated.

When chloroplast pigments absorb light, _____. a) they become reduced b) they lose potential energy c) their electrons become excited d) the Calvin cycle is triggered e) their photons become excited

c) their electrons become excited

The light reactions of photosynthesis use _______ and produce _____. a) carbon dioxide...sugar b) NADPH...NADP⁺ c) water...NADPH d) carbon dioxide...oxygen e) NADPH...oxygen

c) water...NADPH

Of the following, which occurs during the Calvin cycle? a) Light energy is converted to chemical energy. b) ATP is oxidized and NADPH is reduced. c) ATP is reduced and NADPH is oxidized. d) ATP is hydrolyzed and NADPH is oxidized. e) Noncyclic electron flow produces the materials required for the fixation of carbon from carbon dioxide.

d) ATP is hydrolyzed and NADPH is oxidized.

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

d) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.

How is photosynthesis similar in C₄ plants and CAM plants? a) In both cases, only photosystem I is used. 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, rubisco is not used to fix carbon initially. e) In both cases, thylakoids are not involved in photosynthesis.

d) In both cases, rubisco is not used to fix carbon initially.

Which of the following statements correctly describes the relationship between the light reactions and the Calvin cycle? a) The light reactions produce carbon dioxide, ATP, NADPH, all of which are used in the Calvin cycle. b) The light reactions produce ATP and NADPH, both of which are used in the Calvin cycle. c) The light reactions produce ADP and NADP+, both of which are used in the Calvin cycle. d) The light reactions produce water, ATP, NADPH, all of which are used in the Calvin cycle. e) The light reactions produce carbon dioxide and water, all of which are used in the Calvin cycle.

d) The light reactions produce ATP and NADPH, both of which are used in the Calvin cycle.

Which of the following is a product of the light reactions of photosynthesis? a) NADP⁺ and RuBP b) high-energy photons c) water and CO₂ d) oxygen, ATP, and NADPH e) glyceraldehyde-3-phosphate

d) oxygen, ATP, and NADPH

C₄ plants occur more commonly in desert conditions because _______. a) the stomata open at night and close in the day b) they store carbon by incorporation CO₂ into organic acids that are later catabolized c) they produce carbon dioxide internally via photorespiration d) they can fix carbon at the lower CO₂ concentrations that develop when the stomata are closed e) they produce water as a product of their photosynthetic pathways

d) they can fix carbon at the lower CO₂ concentrations that develop when the stomata are closed

How does carbon dioxide enter the leaf? a) through the chloroplasts b) through the roots c) through the thylakoids d) through the stomata e) through the vascular system

d) through the stomata

During photosynthesis, an electron transport chain is used to _____. a) transport NADPH from the light reactions to the Calvin cycle b) transport excited electrons from P700 to an electron acceptor c) transport excited electrons from P680 to an electron acceptor d) transport electrons from photosystem II to photosystem I e) transport excited electrons from P700 to an electron acceptor and transport excited electrons from P680 to an electron acceptor

d) transport electrons from photosystem II to photosystem I

The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from _____. a) carbon dioxide b) glucose c) radioisotopes d) water e) light

d) water

Which of these equations best summarizes photosynthesis? a) 6 CO₂ + 6 O₂→ C₆H₁₂O₆ + 6 H₂) b) C₆H₁₂O₆ + 6 O₂→ 6 CO₂ + 6 H₂O + Energy c) C₆H₁₂O₆ + 6 O₂→ 6 CO₂ + 12 H₂O d) H₂O → 2 H⁺ + 1/2 O₂ + 2e⁻ e) 6 CO₂ + 6 H₂O→ C₆H₁₂O₆ + 6 O₂

e) 6 CO₂ + 6 H₂O→ C₆H₁₂O₆ + 6 O₂

The use of non-C3 and non-CAM plants as crops may be limited in some regions because on hot, dry days, they close their stomata. What happens as a result of closing their stomata? a) It reduces water loss. b) It prevents carbon dioxide from entering the leaf. c) In a process called photorespiration, rubisco binds oxygen instead of carbon dioxide. d) It builds up oxygen from the light reactions in the leaf. e) All of the listed responses are correct.

e) All of the listed responses are correct

Glyceraldehyde-3-phosphate (G3P) is produced in the stroma of chloroplasts. Which of the following statements is most true about this compound? a) It is produced from glucose during glycolysis. b) It is a 3-carbon sugar. c) For every three molecules of CO2, six molecules of G3P are formed but only one molecule exits the cycle to be used by the plant cell. d) For every three molecules of CO2, six molecules of G3P are formed but five molecules must be recycled to regenerate three molecules of RuBP e) All of the listed responses are correct.

e) All of the listed responses are correct.

Which of the following sequences correctly represents the flow of electrons during photosynthesis? a) NADPH→chlorophyll→Calvin cycle b) NADPH→O₂→CO₂ c) NADPH→electron transport chain→O₂ d) H₂O→photosystem I→photosystem II e) H₂O→NADPH→Calvin cycle

e) H₂O→NADPH→Calvin cycle

What is the role of NADP+ in photosynthesis? a) It helps produce ATP from the light reactions. b) It absorbs light energy. c) It forms part of photosystem II. d) It is the primary electron acceptor. e) It forms NADPH to be used in the Calvin cycle.

e) It forms NADPH to be used in the Calvin cycle.

What is the role of NADP+ in photosynthesis? a) It assists chlorophyll in capturing light. b) It acts as the primary electron acceptor for the photosystems. c) As part of the electron transport chain, it manufactures ATP. d) As a component of photosystem II, it catalyzes the hydrolysis of water. e) It is reduced and then carries electrons to the Calvin cycle.

e) It is reduced and then carries electrons to the Calvin cycle.

After 3PGA is phosphorylated, it is reduced by ______. a) CO₂ b) NADP⁺ c) ATP d) ADP e) NADPH

e) NADPH

Which of the following products of the light reactions of photosynthesis is consumed during the Calvin cycle? a) oxygen b) ADP + Pi c) sugar d) water e) NADPH

e) NADPH

The light reactions of photosynthesis generate high-energy electrons, which end up in _____. The light reactions also produce _____ and _____. a) ATP ... NADPH ... oxygen b) oxygen ... sugar ... ATP c) chlorophyll ... ATP ... NADPH d) water ... sugar ... oxygen e) NADPH ... ATP ... oxygen

e) NADPH ... ATP ... oxygen

Based on the work of Engelmann, the wavelengths of light most effective in driving photosynthesis are referred to as _____. a) an effective spectrum b) an absorption spectrum c) an electromagnetic spectrum d) a visible light spectrum e) an action spectrum

e) an action spectrum

In photosynthesis, what is the fate of the oxygen atoms present in CO2? They end up _____. a) as molecular oxygen b) in sugar molecules c) in water d) as molecular oxygen and in sugar molecules e) in sugar molecules and in water

e) in sugar molecules and in water

Which of the following does not occur during the Calvin cycle? a) regeneration of the CO2 acceptor b) carbon fixation c) consumption of ATP d) oxidation of NADPH e) release of oxygen

e) release of oxygen

In a rosebush, chlorophyll is located in _____. a) chloroplasts, which are in mesophyll cells in the thylakoids of a leaf b) mesophyll cells, found within the thylakoids of a leaf's chloroplasts c) thylakoids, which are in mesophyll cells in the chloroplasts of a leaf d) chloroplasts, which are in thylakoids in the mesophyll cells of a leaf e) thylakoids, which are in chloroplasts in the mesophyll cells of a leaf

e) thylakoids, which are in chloroplasts in the mesophyll cells of a leaf

C₄ plants differ from C₃ and CAM plants in that C₄ plants ______. a) use malic acid to transfer carbon dioxide to the Calvin cycle b) are better adapted to wet conditions c) open their stomata only at night d) use PEP carboxylase to fix carbon dioxide e) transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

e) transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

Where do the electrons entering photosystem II come from? a) chlorophyll molecules in the antenna complex b) ATP c) the electron transport chain d) light e) water

e) water

bundle-sheath cell

in C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of a leaf

primary electron acceptor

in the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex with a pair of chlorophyll a molecules an that accepts an electron from them

From the following choices, identify those that are the inputs and outputs of the Calvin cycle. light, O₂,G3P,Glucose,Water, ADP,ATP,NADPH,NADP⁺,CO₂

input: ATP, NADPH, CO₂ output: ADP, NADP⁺, G3P not: light, O₂, glucose

From the following choices, identify those that are the inputs and outputs of light reactions. light, O₂,G3P,Glucose,Water, ADP,ATP,NADPH,NADP⁺,CO₂

input: light, water, ADP, NADP⁺ output: ATP, O₂, NADPH not: G3P, glucose, CO₂

mesophyll

leaf cells specialized for photosynthesis. in C3 and CAM plants, mesophyll cells are located between the upper and lower epidermis; in C4 plants, they are located between the bundle-sheath cells and the epidermis

photosystem II

one of two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center

rubisco

ribulose bisphosphate (RuBP) carboxylase, the enzyme that catalyzes the first step of the Calvin cycle ( the addition of CO2 to RuBP)

1. Sun emits photons at all wavelengths. 2. Prism dispereses sunlight into individual wavelengths. 3. Alga's photosynthetic pigments absorb photons at specific wavelengths. 4. Absorbed photons drive photosynthesis in alga. 5. Alga gives off oxygen as it photosynthesizes. 6. Bacteria attracted to regions of highest oxygen concentration. 7. Number of bacteria in different wavelength

s

Sunlight provides energy for photosynthesis. Photosynthesis occurs in chloroplasts. Chloroplasts contain the pigment chlorophyll. Photosynthesis produces oxygen and sugar. Carbon dioxide provides carbon for photosynthesis. Oxygen and sugar are inputs for cellular respiration. Cellular respiration occurs in mitochondria. Cellular respiration produces carbon dioxide and ATP.

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visible light

that portion of the electromagnetic spectrum that can be detected as various colors by the human eye, ranging in wavelength from about 380 nm to about 750 nm

photosynthesis

the conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes

stroma

the dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water.

wavelength

the distance between crests of waves, such as those of the electromagnetic spectrum

electromagnetic spectrum

the entire spectrum of electromagnetic radiation, ranging in wavelength from less than a nanometer to more than a kilometer

light reactions

the first of two major stages in photosynthesis (preceding the Calvin cycle). these reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.

carbon fixation

the initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).

photophosphorylation

the process of generating ATP form ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis

absorption spectrum

the range of a pigment's ability to absorb various wavelengths of light; also a graph of such a range.

calvin cycle

the second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate