Deck 9: Photosynthesis and Cellular Respiration

Question 1

Which of the following applies to chloroplasts?

A)They have an intermembrane space and a matrix.
B)They have three membrane-enclosed compartments.
C)Unlike mitochondria, they lack a stroma.
D)They carry out both photosynthesis and respiration.

Answer 1

B

Question 2

What is the role of water in photosynthesis?

A)Water provides a phosphate group to ATP.
B)Water captures light energy and transfers it to the electron transport chain.
C)Water provides replacement electrons to the reaction center chlorophyll.
D)Water combines with carbon dioxide (CO2) to make glucose.

Answer 2

C

Question 3

Stomata admit CO₂ but also facilitate the loss of water; plants must regulate their stomata carefully or risk dehydration. A reasonable hypothesis associated with the global increase in atmospheric CO₂ is that plants will

A)evolve lower stomatal densities and reduce the potential for desiccation.
B)grow larger and more rapidly than they presently do.
C)keep their stomata closed most of the time to minimize carbon dioxide poisoning.
D)increase stomatal densities to take advantage of the abundance of CO2.

Answer 3

A

Question 4

Photosynthesis and cellular respiration are both complementary and relatively balanced, but early in the history of life on Earth photosynthesis appears to have dominated, as evidenced by the

A)accumulation of atmospheric oxygen.
B)declines in historic sea level as photosynthetic organisms consumed water.
C)gradual warming of Earth's climate as CO2 slowly accumulated.
D)all of the above

Question 5

During the process of photosynthesis, plants capture the kinetic energy of moving photons and transform it into potential energy in the form of

A)pyruvate.
B)stroma.
C)chemical bonds.
D)thylakoid disks.

Question 6

As an energy carrier, ATP differs from NADPH in that

A)ATP carries less energy than NADPH.
B)ATP transfers energy through redox reactions, whereas NADPH uses phosphorylation.
C)NADPH is involved in a larger variety of chemical reactions than ATP.
D)NADPH is made by Photosystem I, whereas ATP is made by Photosystem II.

Question 7

The energy carriers NADPH and NADH differ structurally. Functionally they

A)are quite similar; each transports electrons and hydrogen ions released in catabolic pathways.
B)are quite similar; each transports electrons and hydrogen ions to anabolic pathways.
C)are somewhat different; NADPH receives electrons and hydrogen from catabolic processes, whereas NADH delivers those items to anabolic processes.
D)are somewhat different; NADH receives electrons and hydrogen from catabolic processes, whereas NADPH delivers those items to anabolic processes.

Question 8

Biologists believe that in the earliest version of photosynthesis the energized photosystem electron simply cycled back to the chlorophyll molecule. What limitations would such a system impose?

A)No molecular oxygen would be generated.
B)No electrons would be available to reduce the carbon in CO2.
C)Cells could produce ATP but not sugars.
D)all of the above

Question 9

What is the importance of photosynthesis to organisms other than plants?

A)All other organisms require oxygen for life processes.
B)The sugars made during photosynthesis are building blocks of DNA.
C)All cells must have chloroplasts in order to survive.
D)Photosynthesis captures energy that other organisms access when they eat either plants or organisms that eat plants.

Question 10

NAD⁺ is an energy carrier in living organisms that couples

A)oxygen production and the generation of carbon dioxide during cellular respiration.
B)the synthesis of ATP with the synthesis of water.
C)photosynthesis and metabolism.
D)the catabolic aspects of cellular respiration with the synthesis of ATP.

Question 11

The illustration below indicates that photosynthesis and cellular respiration are both complementary and balanced; the existence of fossil fuels like coal and petroleum suggest in the past,

A)the amount of photosynthesis occurring exceeded the amount of cellular respiration.
B)sugars were only one of several products of photosynthesis.
C)reduced carbon-rich molecules could be produced independently from the photosynthetic process.
D)the energy release from respiration must have exceeded energy use in photosynthesis.

Question 12

Cells use a variety of metabolic pathways to construct ATP, but each concludes with the same step. Which of the following describes the final step by which ADP becomes ATP?

A)photosynthesis
B)phosphorylation
C)carbon fixation
D)electron transfer

Question 13

Examine the illustration below; which statement best summarizes the contribution of Photosystem I (PSI)during photosynthesis?

A)PSI provides the initial energy boost to the electrons on their way to Photosystem II (PSII).
B)PSI generates the excited electrons that initially accumulate within the thylakoid space and eventually drive ATP synthesis.
C)PSI generates the high-energy electrons that are transported by NADPH to the Calvin cycle and will eventually reduce the carbon in CO2.
D)By cycling between reduced and oxidized states, PSI regulates the transmembrane passage of protons between the stroma and the thylakoid space.

Question 14

The energetics of photosynthesis often overshadows the importance of carbon fixation, but without this vital process,

A)carbon dioxide levels would rise uncontrollably, making the Earth too warm to support life.
B)atmospheric oxygen levels would be too low to support life on Earth.
C)carbon atoms would not be readily available in biologically useful forms, causing organisms to grow and reproduce very slowly.
D)all of the above

Question 15

Each time you take a breath you are bringing in the oxygen you need to stay alive. The ultimate source of the oxygen used by all aerobic organisms comes from a reaction that

A)degrades carbon dioxide.
B)hydrolyzes ATP.
C)splits water.
D)reduces NADPH.

Question 16

Since plants are able to capture energy from the sun, why do they need to pass that energy through the chemical reactions necessary to produce ATP?

A)ATP allows the energy to be stored for later use or transferred to other chemical reactions.
B)Chloroplasts are unable to use the energy they capture from the sun.
C)Producing ATP allows the plant to destroy excess energy that was captured from the sun.
D)The mitochondria that capture the sun's energy are unable to use it for respiration.

Question 17

Which of the following molecules carries electrons that will be used to reduce other molecules in an electron transport chain?

A)ATP
B)NADH
C)CO2
D)ADP

Question 18

The chemical 3-(3,4-dichloro-phenyl)-1,1-dimethylurea (DCMU)blocks the movement of electrons at the point indicated by the black, downward-pointing arrow in the figure below.
Which of the following would be an immediate effect of treating a chloroplast with this drug?

A)Water molecules would be split at a faster rate than when the drug is not present.
B)The amount of NADPH produced by the light reactions would increase.
C)A proton gradient would not be created, so ATP could not be made.
D)The Calvin cycle would not occur.

Question 19

Which of the following statements describe the function of the electron transport chain (ETC)in photosynthesis?

A)As electrons move through the ETC, they release energy that is used to concentrate protons in the thylakoid lumen.
B)As electrons move through the ETC, they catalyze the formation of ATP.
C)The ETC releases CO2 from glucose.
D)The ETC captures and stores the electrons given off by NADPH.

Question 20

Several energy carriers can be found in eukaryotic cells; the most versatile, as indicated in the illustration below, is

A)ATP.
B)NADPH.
C)NADH.
D)FADH2.

Question 21

Which of the following statements comparing photosynthesis and cellular respiration is accurate?

A)Photosynthesis is a catabolic pathway, whereas cellular respiration is an anabolic pathway.
B)Water is formed during photosynthesis, but broken apart during cellular respiration.
C)Both photosynthesis and cellular respiration require electron transport chains.
D)Both photosynthesis and cellular respiration produce CO2 as metabolic end products.

Question 22

All of the following elements can be found in the photosynthetic intermediary molecules leading to sugar; which element does not remain in the final product?

A)carbon
B)phosphorous
C)hydrogen
D)oxygen

Question 23

The enzyme rubisco is important to the process of

A)catabolism.
B)fermentation.
C)glycolysis.
D)carbon fixation.

Question 24

The three stages of aerobic catabolism are

A)photosynthesis, glycolysis, and oxidative phosphorylation.
B)glycolysis, the Krebs cycle, and oxidative phosphorylation.
C)glycolysis, fermentation, and the Krebs cycle.
D)photosynthesis, the Krebs cycle, and fermentation.

Question 25

During photosynthesis, energized electrons flow from

A)Photosystem I to Photosystem II.
B)the reaction center to the antenna complex.
C)Photosystem II to Photosystem I.
D)the stroma to the intermembrane space.

Question 26

A funnel is used to channel substances collected over a wide area into a narrow-necked container. A funnel might be a good analogy for the

A)reaction center.
B)antenna complex.
C)thylakoid.
D)stoma.

Question 27

It is OK to say that your brain is solar powered, because

A)mitochondria in plant cells convert solar power to the chemical power that is used to run your brain.
B)cellular respiration is powered by sunlight.
C)the antenna complex in chloroplasts acts like a tiny solar panel, collecting sunlight to make the sugars that you consume to run your brain.
D)mitochondria in plant cells use solar power to split water molecules, creating the energy that runs your brain.

Question 28

NADP⁺ is

A)oxidized by Photosystem I.
B)reduced by Photosystem I.
C)reduced by Photosystem II.
D)oxidized by Photosystem II.

Question 29

The ETC in the chloroplast or mitochondrion gradually lower the energy content of an electron as it passes from carrier to carrier, similar to the reduction in energy content of a

A)cannonball that reaches the high point of its flight and then returns to the ground.
B)bowling ball bouncing down a flight of stairs and landing temporarily on each step.
C)pair of sunglasses that intercepts ultraviolet radiation before it reaches your eyes.
D)recently baked pie cooling on the counter before it can be cut and eaten.

Question 30

During exercise, the increase in respiration rate and heartbeat speed are driven by the need to replenish the oxygen used to support

A)lactic acid fermentation.
B)carbon dioxide synthesis in the lungs.
C)oxidative phosphorylation in muscle cell mitochondria.
D)in-the-dark reactions of photosynthesis.

Question 31

The diagram below shows the Calvin cycle, which is a series of enzymatic reactions that manufacture sugars.
How many times must this cycle "turn" to make one molecule of glucose (six carbons)?

A)1
B)3
C)6
D)12

Question 32

A fermentation is an oxidative pathway where the electrons released from a nutrient molecule are transferred to molecules created by the catabolism of the nutrient. What molecule receives electrons in lactic acid fermentation?

A)pyruvate
B)glucose
C)lactic acid
D)ethanol

Question 33

The burning pain in your muscles during strenuous exercise is a result of

A)the buildup of lactic acid during fermentation.
B)signals sent to the nervous system by O2-starved cells.
C)the accumulation of pyruvate in the absence of oxidative phosphorylation.
D)the lack of ATP needed to regulate the pain receptors in your muscle cells.

Question 34

Glycolysis is an anaerobic process, indicating that the glycolytic reactions

A)require no oxygen.
B)produce molecular oxygen.
C)produce ATP.
D)produce citric acid.

Question 35

The photosynthetic reactions that are dependent on light occur in the

A)thylakoid membrane.
B)stroma.
C)cytosol.
D)nucleus.

Question 36

What best summarizes the events of the Calvin cycle?

A)The cycle uses ATP and NADPH to produce sugars.
B)The cycle moves electrons from Photosystem II to Photosystem I.
C)The cycle moves light-energized electrons to Photosystem II.
D)The cycle absorbs light from the light reactions.

Question 37

Because inorganic carbon cannot be used by living organisms to build biological molecules, carbon fixation may be the most important metabolic process in the biosphere; if so, that would make _____ the most important enzyme in the biosphere.

A)chlorophyll
B)ATP synthetase
C)sucrase
D)rubisco

Question 38

Glycolysis occurs in the _____ of a cell.

A)nucleus
B)chloroplast
C)mitochondrion
D)cytosol

Question 39

The number and arrangement of membranes within a chloroplast are important to the chloroplast's functions. How would the absence of these membranes affect the manufacture of ATP within a chloroplast?

A)The chloroplast would be unable to maintain the proton gradient required for ATP production.
B)The chloroplast would be unable to capture ATP directly from the sun.
C)The chloroplast would be unable to perform the Calvin cycle.
D)The chloroplast would be unable to perform anaerobic respiration.

Question 40

The outcome of the Calvin cycle is the

A)capture of energy from sunlight.
B)synthesis of sugars like glucose, fructose, and sucrose.
C)production of pyruvate.
D)breakdown of complex molecules and the subsequent release of energy.

Question 41

The Krebs cycle takes place in the

A)mitochondrial matrix.
B)cytosol.
C)thylakoid membrane.
D)outer mitochondrial membrane.

Question 42

Most of the oxidation reactions that produce NADH in a cell take place in

A)the Krebs cycle.
B)glycolysis.
C)photosynthesis.
D)the electron transport chain.

Question 43

In mitochondria, the energy released by electrons as they move through the electron transport chain is used to transport

A)electrons from the thylakoid matrix to the cytosol.
B)acetyl CoA into the Krebs cycle.
C)protons into the mitochondrial intermembrane space.
D)pyruvate into the first reaction of glycolysis.

Question 44

____________________ reactions break down and gradually oxidize food molecules to produce energy.

Question 45

The process that produces ATP from sugars begins with glycolysis; when fatty acids are used the process begins with

A)oxidative phosphorylation.
B)the Calvin cycle.
C)the electron transport chain.
D)the Krebs cycle.

Question 46

Although ____________________ has less energy than other energy carriers, it is more versatile because it can be used in a larger variety of chemical reactions.

Question 47

Biologists believe that the change in the HIF2a gene frequency among Tibetans may be the fastest case of human evolution yet discovered. What is the selection pressure affecting this gene?

A)The low atmospheric pressures experienced on the high-altitude Tibetan Plateau.
B)The low atmospheric concentration of O2 that occurs at high altitude.
C)The increased solar, particularly UV, radiation experienced at high altitude.
D)A diet consisting primarily of high-altitude-tolerant crops.

Question 48

World-class sprinters typically do not breathe during the 9+ seconds needed to complete 100 meters. What does this suggest about their energy production?

A)It must be mitochondrial, with oxygen provided by one big breath at the beginning of the sprint.
B)It must be mitochondrial, with oxygen provided by circulating hemoglobin already saturated with oxygen.
C)It must be glycolytic; the process is entirely anaerobic and the race will be over before NADH+ reserves are depleted.
D)It must be fermentative, which explains why most sprinters experience cramping once the race ends.

Question 49

An electron transport chain is made up of a group of electron-accepting ____________________ embedded in a membrane.

Question 50

Acetyl CoA is a substrate of

A)glycolysis.
B)the Krebs cycle.
C)the electron transport chain.
D)the Calvin cycle.

Question 51

The inner membrane of a mitochondrion is highly folded. Which of the following explains why this is the case?

A)The folds protect the proteins in the inner membrane from the toxic by-products of cellular respiration.
B)The folds increase the space available for electron transport chains, increasing the efficiency of ATP production.
C)The extra folds make the mitochondrion more efficient at capturing carbon dioxide.
D)The antenna complexes in the inner membrane form clusters that force the membrane into folds.

Question 52

The conversion of inorganic carbon from air into the carbon atoms found in all living organisms is known as carbon ____________________.

Question 53

The Krebs cycle produces

A)NADH and carbon dioxide.
B)water and carbon dioxide.
C)ADP and NADP+.
D)acetyl CoA and sugars.

Question 54

Light consists of massless particles called photons, each of which propagates through space with a wavelike oscillation; the ____________________ the wavelength the greater the energy content.

Question 55

The figure below is a diagram of the inner mitochondrial membrane.
How did the protons (H⁺)in this diagram become concentrated on one side of the membrane?

A)The H+ were pumped across the membrane by the electron transport chain.
B)The H+ were released when ATP phosphorylated a membrane protein.
C)ATP was used to pump the H+ across the membrane.
D)Oxygen must release two H+ in the intermembrane space before it can move into the matrix.

Question 56

The light reactions in photosynthesis result in three output products: molecular oxygen, ATP, and ____________________.

Question 57

NAD⁺ becomes NADH when it gains two high-energy ____________________ and one proton.

Question 58

Biologists believe that Earth's early life-forms were exposed to an atmosphere with no molecular oxygen and had not yet evolved the Krebs cycle. If so, alcoholic fermentation would have been particularly critical to life because without the pathway

A)ethanol would not be available as a nutrient for other consumers.
B)lactic acid would accumulate and disable prokaryotic muscle cells.
C)carbon could not be recycled back into the biosphere for use by producers.
D)the only source of NADH for electron transport would be from glycolysis and ATP production would be greatly reduced.

Question 59

The energy source that makes oxidative phosphorylation possible comes from

A)phosphate group transfers from ATP.
B)electrons transferred from NADPH.
C)electrons transferred from NADH.
D)electrons removed from CO2 during its oxidation.

Question 60

During alcoholic fermentation, pyruvate is converted to ethanol in order to

A)increase the efficiency of cellular respiration by producing additional molecules of ATP.
B)release O2 as a by-product so that cellular respiration can continue.
C)create lactic acid to stimulate muscle contraction.
D)recycle NADH back into NAD+ so that the cell can continue glycolysis.

Question 61

The NADH produced by the Krebs cycle donates electrons to the electron transport chain.

Question 62

Energy is used to force protons from the thylakoid space back into the stroma.

Question 63

The energy needed to produce the flash of a firefly originally came from sunlight.

Question 64

Cellular respiration is, essentially, the opposite of photosynthesis.

Question 65

In mitochondria, ATP is produced in conjunction with proteins in the membrane that surrounds a region in the mitochondrion known as the ____________________.

Question 66

Only animal cells carry out oxidative phosphorylation.

Question 67

Electrons gain energy as they move through the electron transport chain.

Question 68

The green pigment most commonly associated with photosynthesis is ____________________.

Question 69

____________________ organisms require oxygen in order to extract energy from food.

Question 70

Not all visible light supports photosynthesis; only those wavelengths colored ____________________ and ____________________ can excite the chlorophyll molecules in an antenna complex.

Question 71

You have been shrunk to molecular size and find yourself in a chamber in a chloroplast where protons are being pumped into another chamber. You are in the ____________________.

Question 72

During the Calvin cycle, the enzyme rubisco combines a ____________________-carbon compound with CO₂ to form an unstable carbohydrate [the answer is a number].

Question 73

You have been shrunk to molecular size and find yourself in a mitochondrial chamber where protons are being pumped out across a membrane into another chamber. You are in the mitochondrion's ____________________.

Question 74

Although several negative factors are associated with chronic exposure to high altitude, the decline in ____________________ is most likely to have been responsible for the rapid evolution of the HIF2a gene.

Question 75

The innermost membrane in a chloroplast is the ____________________ membrane.

Question 76

ATP synthase is a protein involved in the redox reactions of the electron transport chain.

Question 77

Fermentation produces more ATP molecules than aerobic respiration does.

Question 78

The mitochondria of plants contain thylakoids.

Question 79

Alcohol is a by-product of fermentation by yeast.

Question 80

The muscles of a very active organism would contain fewer mitochondria than the muscles of a less active organism.