BIOL411 Exam 3 Sample Questions

Like glycolysis, pyruvate oxidation produces both pyruvate and acetyl-CoA. These two products feed directly into the citric acid cycle and are the reactants for the cycle. a) true b) false

b

Many photosynthetic prokaryotes are capable of cyclic electron transport only. It is likely that such organisms can ____ but not ____. A) Produce ATP; reduce H2O B) Produce ATP; reduce CO2 C) Produce NADPH; reduce CO2 D) Produce NADPH; oxidize H2O E) Reduce CO2; synthesize carbohydrates

b

Organisms that derive both their energy and carbon from organic compounds are classified as: A) Photoautotrophs B) Chemoheterotrophs C) Photoheterotrophs D) Chemoautotrophs E) Chemolithotrophs

b

Organisms that derive both their energy and carbon from organic compounds are: a) photoheterotrophs. b) chemoheterotrophs. c) chemoautotrophs. d) photoautotrophs. e) chemolithotrophs.

b

Oxidation is the gain of electrons. a) true b) false

b

Phosphorylating glucose during phase 1 of glycolysis: a) releases phosphorylated glucose from cells. b) destabilizes the glucose molecule so that it can be broken down in phase 2. c) provides electrons to reduce NAD+ in phase 3. d) provides electrons to reduce FADH in phase 3. e) None of the other answer options is correct.

b

Pyruvate oxidation is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed. a) true b) false

b

Pyruvate oxidation produces a large amount of ATP. a) true b) false

b

The degree of disorder, or number of microstates, is called: a) work. b) entropy. c) energy. d) ecology. e) potential difference.

b

The first phase of glycolysis requires the input of two ATP molecules. It is therefore: a) exergonic. b) endergonic. c) oxidative. d) reducing. e) None of the other answer options is correct.

b

From its ground state, photosystem II can: a) pull electrons from H2O. b) absorb light energy. c) pass electrons to photosystem I. d) pull protons from H2O. e) emit light energy.

b

In chemical reactions, most of the entropy increase occurs as: a) ATP production. b) heat. c) chemical energy. d) electrical energy. e) glycolysis.

b

The inputs to glycolysis do not include: a) NAD+. b) glucose. c) ADP. d) NADH. e) Pi.

d

An avalanche is an example of ________ energy A) Kinetic B) Chemical C) Potential D) Metabolic E) Thermal

a

Another name for acetyl-CoA synthesis, is: a) pyruvate oxidation. b) oxidative phosphorylation. c) glycolysis. d) substrate-level phosphorylation. e) pyruvate reduction.

a

Antennae accompany reaction centers, promoting _____. a) energy transfer b) electron transfer c) fluorescence d) heat loss e) H+ transfer

a

Assuming that all is working properly, which of the following is at a higher energy level? a) An excited-state antenna chlorophyll b) An excited-state reaction center chlorophyll

a

Glycolysis, the breakdown of one glucose into two pyruvate, is an example of a reaction that is: A) Exergonic and catabolic B) Exergonic and anabolic C) Endergonic and catabolic D) Endergonic and anabolic

a

High temperatures increase reaction rates but lower rubisco selectivity for CO2 versus O2. High leaf temperatures thus: A) Increase photorespiration rates. B) Decrease photorespiration rates. C) Increase cellular respiration. D) Decrease RuBP carboxylation. E) Increase RuBP carboxylation.

a

How did the earliest organisms on Earth most likely produce ATP? a) by glycolysis b) by the citric acid cycle c) by pyruvate oxidation d) by oxidative phosphorylation

a

Imagine that you are talking with one of your friends. He states that evolution has actually violated the second law of thermodynamics because complex living organisms are more ordered than the nucleic acids, amino acids, and other molecules that compose them. Why doesn't evolution contradict the second law of thermodynamics? a) Even though evolution may decrease the entropy of living organisms, it increases the entropy of the Earth (or the universe) as organisms release heat. b) Because evolution takes place over millions of years, the loss of entropy is negligible and thus the laws of thermodynamics are not violated. c) Evolution is a biological process, and biological processes do not have to conform to the laws of physics. d) Evolution doesn't affect entropy, as living organisms eventually die and become "disordered." e) Evolution actually does violate the second law of thermodynamics, and this fact is problematic for scientists.

a

Imagine that you discover a microbial deep-sea organism that can derive energy from (inorganic) hydrogen gas (H2). However, this microbe can also synthesize organic compounds from carbon-containing inorganic molecules in the ocean. This microbe is a: a) chemoautotroph. b) photoautotroph. c) photoheterotroph. d) phototroph. e) chemoheterotroph.

a

Imagine that you walk out of your warm house on a cold winter's day. What is different between the air inside and outside of your house in this scenario? a) The molecules in the warm air of your house are moving faster than those outside. b) The molecules in the warm air have more potential energy than those outside. c) The molecules in the cold air outside of your house are moving faster than those inside. d) The molecules in the warm air inside of your house have less entropy than those outside. e) The molecules in the cold air outside of your house have more kinetic energy than those inside.

a

In ______, large molecules are broken down and ATP is produced. a) catabolism b) anabolism c) diffusion d) chemiosmosis e) active transport

a

In addition to chlorophylls, light-harvesting antennae include other pigments. What is the benefit of these additional pigments? a) narrower range of wavelength reflection b) increased structural stability of the antenna c) enhanced resonance transfer d) tighter binding of the antennae to the thylakoid e) lower anti-oxidant capacity

a

In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water. a) oxidized; reduced b) phosphorylated; deoxygenated c) deoxygenated; phosphorylated d) reduced; oxidized e) oxidized; oxidized

a

In cellular respiration, oxygen: a) gains electrons and is an oxidizing agent. b) loses electrons and is a reducing agent. c) gains electrons and is a reducing agent. d) loses electrons and is an oxidizing agent. e) None of the other answer options is correct.

a

In the Calvin cycle, ATP is required to: a) donate a phosphate group to 3-PGA. b) reduce 3-PGA. c) carboxylate RuBP. d) reduce triose phosphates. e) reduce RuBP.

a

In the light-dependent reactions of photosynthesis, light energy is captured and stored as potential energy. In which of the following is this energy stored in the light-dependent reactions? a) NADPH, ATP, and an electrochemical gradient. b) NADPH and ATP c) NADPH, ATP, and carbohydrate molecules d) an electrochemical gradient e) carbohydrate molecules

a

Organic molecules store _____energy in their _____ bonds. a) potential; covalent b) potential; ionic c) kinetic; hydrogen d) kinetic; covalent e) kinetic; ionic

a

Photosystem II and photosystem I differ in: a) H+ production, and electron donors and acceptors. b) H+ production and electron donors. c) H+ production. d) electron donors and acceptors. e) plants and algae.

a

Rubisco is characterized by: a) slow catalysis and the ability to use two substrates. b) slow catalysis. c) the ability to use two substrates. d) fast catalysis.

a

Suppose that three critical amino acids in the active site of a specific enzyme are leucine, tryptophan, and alanine. Which of the following characteristics would you predict the substrate to possess in order to bind the active site of this enzyme? A) Hydrophobic B) Hydrophilic, with a negative charge C) Hydrophilic, with a positive charge D) Hydrophilic, without a charge (polar)

a

Suppose that, in a given reaction, the enthalpy (H) increases by 10 units, and the disorder (TS) increases by 12 units. Would this reaction be considered spontaneous? A) Yes B) No

a

The Calvin cycle includes 15 enzymes, most of which are involved in: a) RuBP regeneration. b) starch synthesis. c) RuBP carboxylation. d) reduction. e) ATP synthesis.

a

The Z scheme refers to: a) the changes in the energy level of electron donors during the photosynthetic electron transport chain. b) proton translocation. c) the use of H2O as an electron source. d) the path of electrons between photosystem II and cytochrome b6f. e) electron transport.

a

The products of the Calvin cycle are 3-carbon sugars. a) true b) false

a

What would happen to ATP synthase activity if NAD+levels were low? A) It would speed up. B) It would slow down. C) It would not change.

a

When fats are used as an energy source the fatty acids are broken down to acetyl-CoA. This means that fats bypass the reactions of _____ and enter the respiratory pathway as an intermediate in _____. A) Glycolysis; the citric acid cycle B) Fermentation; glycolysis C) Glycolysis; oxidative phosphorylation D) The citric acid cycle; glycolysis E) Oxidative phosphorylation; fermentation

a

Which of the following correctly lists the three steps of the Calvin cycle? a) carboxylation, reduction, and regeneration b) oxidation, reduction, and carboxylation c) carboxylation, ATP synthesis, and regeneration d) reduction of carbon dioxide, reduction of NADPH, regeneration of RuBP

a

Which of the following statements is true regarding a reducing agent? a) It loses electrons. b) It is usually oxygen. c) It is an electron acceptor. d) It gains electrons. e) It is never oxidized.

a

Which of the following would occur if a plant was exposed to a compound that partially inhibits NADP+ reductase? A. Decreased triose phosphate production B. Decreased levels of NADP+ in the chloroplast C. Decreased levels of ATP in the chloroplast D. Decreased rate of cyclic electron transport

a

Imagine that a eukaryotic cell carries a mutation impairing its ability to phosphorylate glucose during glycolysis. What is a likely result of this mutation? a) Because phosphorylation stabilizes glucose, glucose would spontaneously form pyruvate. b) Glucose could move out of the cell, slowing cellular respiration. c) High (possibly toxic) levels of glucose would accumulate in the cell. d) More pyruvate would be formed at the end of glycolysis. e) Without the phosphorylation of glucose, glycolysis would consist entirely of exergonic reactions.

b

Imagine that you exhale after a deep breath. Which of the following are you NOT exhaling? A) CO2 B) Waste products of glycolysis C) Waste products of pyruvate oxidation D) Waste products of the citrate cycle E) Waste products of pyruvate oxidation and the citrate cycle

b

As plant cells rely on energy obtained directly from the sun to carry out cellular processes, sugars are only used as backup energy sources for plants on cloudy days. a) true b) false

b

At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of: a) one pyruvate molecule. b) two pyruvate molecules. c) two ATP molecules. d) two NADH molecules. e) four ATP molecules.

b

Cyclic electron transport enhances ATP production because: a) ADP production increases. b) electrons are transferred from ferredoxin to plastoquinone. c) proton translocation decreases. d) photosystem I pumps more protons. e) cyclic electron transport is more energy efficient than linear electron transport.

b

Escherichia coli bacteria in your colon are categorized as: a) photoautotrophs. b) chemoheterotrophs. c) photoheterotrophs. d) chemoautotrophs.

b

The regeneration of RuBP typically limits the rate of photosynthesis under low light intensities. This is because: a) RuBP regeneration requires ADP. b) RuBP regeneration requires ATP. c) RuBP regeneration is part of the "dark reactions." d) photosynthesis occurs only in high light. e) None of the answer options is correct.

b

The second law of thermodynamics states that: a) combustion engines are 100% efficient. b) there is an increase in disorder in the universe over time. c) energy cannot be created or destroyed. d) only eukaryotic cells can produce ATP. e) the universe becomes more orderly over time.

b

Very low concentrations of detergent make holes in membranes, which allows small molecules and ions to leak through without damaging proteins. In isolated mitochondria exposed to detergent, the molecules of the electron transport chain and ATP synthase remain undamaged. Do you expect ATP synthesis to continue in the presence of low concentrations of detergent? A) Yes, because all enzymes and electron carriers are functional. B) No, because with a leaky membrane the proton gradient cannot be maintained. C) No, because leaky membranes do not allow NADH and FADH2 to donate their electrons to the electron transport chain. D) No, because leaky membranes inhibit glycolysis.

b

What would happen to ATP synthase activity if NADH levels were low? A) It would speed up. B) It would slow down. C) It would not change.

b

What would happen to ATP synthase activity if oxygen levels were low? A) It would increase. B) It would decrease. C) It would not change.

b

What would happen to the proton gradient if NADH levels were low? A) It would get stronger. B) It would get weaker. C) It would not change.

b

What would happen to the rate of ATP synthase activity if ATP was very abundant? A) It would increase. B) It would decrease. C) It would not change.

b

What would happen to the rate of ATP synthase activity if the proton gradient became weaker? A) It would increase. B) It would decrease. C) It would not change.

b

What would happen to the rate of the citric acid cycle if ATP was not being used? A) It would speed up. B) It would slow down. C) It would not change.

b

What would happen to the rate of the electron transport chain if ATP concentrations were high? A) It would speed up. B) It would slow down. C) It would not change.

b

What would happen to the rate of the electron transport chain if acetyl-CoA was low? A) It would speed up. B) It would slow down. C) It would not change.

b

When a single pyruvate is converted to acetyl-CoA, the other products of the reaction are: a) ATP and NADH. b) NADH and CO2. c) CO2 and ATP. d) Pi and FADH2. e) FADH2 and ATP.

b

Which of the following are products of the light-dependent reactions of photosynthesis that are required by reactions in the Calvin cycle? a) ATP and oxygen b) ATP and NADPH c) NADP+ and oxygen d) Water and NADPH

b

Which of the following has the most entropy, individual nucleotides or a nucleic acid? a) a nucleic acid b) individual nucleotides c) The entropy of the nucleotides and nucleic acid would be the same. d) It is impossible to determine the entropy of nucleotides or a nucleic acid.

b

Which of the following is true concerning the Calvin cycle and light-harvesting reactions of photosynthesis? a) They take place in different organelles. b) They take place in different compartments of the same organelle. c) They take place in different types of cells in the plant d) None of the other answer options is correct.

b

Which of the following statements is true regarding pyruvate oxidation? a) Pyruvate oxidation ends with the oxidation of an acetyl group, which forms CO2. b) Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis. c) Like glycolysis, pyruvate oxidation is carried out in the mitochondria. d) Pyruvate oxidation directly follows the citric acid cycle during cellular respiration.

b

You have entered a 5K race. As you finish the last 50 yards, you are breathing harder than at the start of the race and sweating profusely. This is an example of the _____ law of thermodynamics because _____ is increasing. a) first; entropy b) second; entropy c) first; body temperature d) second; body temperature e) None of the other answer options is correct.

b

All cells able to carry out photosynthesis have: a) mitochondria. b) chloroplasts. c) a plasma membrane. d) chloroplasts and mitochondria. e) chloroplasts, mitochondria, and a plasma membrane.

c

Chemicals called uncouplers can make membranes permeable to small molecules and ions. What effect might un-couplers have on photosynthesis? a) increased ATP production because cyclic electron transport would increase b) decreased ATP production because the proton gradient would increase c) decreased ATP production because the proton gradient would decrease d) decreased NADPH production because the proton gradient would increase e) decreased NADPH production because the proton gradient would decrease

c

Consider the refrigerator in your kitchen. Based on what you know about the first and second laws of thermodynamics, how does a refrigerator most likely work? a) A refrigerator destroys any heat in its interior, or in the food it contains. b) A refrigerator creates new energy, although it is in the form of cold rather than heat. c) A refrigerator removes heat from its interior and transports this energy outside, into the kitchen. d) A refrigerator removes the potential energy contained within food. e) A refrigerator both destroys any heat in its interior, or in the food it contains, and creates new energy in the form of cold.

c

During their experiments with chlorella, Calvin and Benson found no free glucose. Why do you think this is? a) Glucose would cause H2O to leave the Chlorella cells. b) Glucose takes too long to synthesize. c) Glucose is stored as starch. d) Glucose is an isomer of fructose. e) Green algae do not respire when illuminated.

c

Imagine that several atoms bond to form a carbohydrate, creating a more orderly system. Which of the following statements is true regarding the universe after this carbohydrate forms? a) The energy of the universe increases. b) The energy of the universe decreases. c) The entropy of the universe increases. d) The entropy of the universe decreases. e) Both the energy and entropy of the universe increases.

c

In eukaryotic cells, glycolysis occurs in: A) The nucleus B) The mitochondrial matrix C) The cytoplasm D) The endoplasmic reticulum E) Vacuoles

c

In the Calvin cycle, NADPH is: a) phosphorylated. b) reduced. c) oxidized. d) None of the answer options is correct. e) oxidized and reduced.

c

In the second phase of glycolysis: a) phosphate groups are added to glucose. b) ATP is generated by oxidative phosphorylation. c) phosphorylated sugar molecule is cleaved and the products rearranged. d) NAD+ is reduced to NADH. e) ATP is generated by substrate-level phosphorylation.

c

In which stage of cellular respiration is the greatest amount of chemical energy harvested from molecules that are derived from food? A. Glycolysis B. Pyruvate Oxidation C. The citric acid cycle D. The electron transport chain E. All of the above extract equal amounts of energy from food molecules.

c

Many photosynthetic prokaryotes are capable of cyclic electron transport only. It is likely that such organisms can _____ but not _____. a) produce NADPH; reduce CO2 b) produce ATP; reduce H2O c) produce ATP; reduce CO2 d) produce NADPH; oxidize H2O e) reduce CO2; synthesize carbohydrates

c

Nearly all cells use ATP as their primary energy source. This is evidence that: a) fossil fuels are composed of ATP. b) life continues to evolve and use novel energy sources. c) the use of ATP by cells began eons ago and has been conserved over time. d) ATP evolved recently (in the last 100 years) as a potential source of energy. e) only eukaryotic cells can produce ATP.

c

Organisms with only one photosystem CANNOT: A) Reduce CO2 B) Reduce H2O C) Produce O2 D) Oxidize H2S E) Reduce NADP+

c

Photosystem II and photosystem I differ in: A) H+ production. B) H+ production and electron donors. C) H+ production and electron donors and acceptors. D) Electron donors and acceptors. E) Plants and algae.

c

Suppose you discovered a mutant strain of spinach in which the thylakoid membranes were slightly permeable to protons, thus allowing a slow leakage. How might this defect affect the yield of ATP and/or NADPH from chloroplasts? A) NADPH yield would decrease B) NADPH yield would increase C) ATP yield would decrease D) ATP yield would increase E) NADPH and ATP yield would decrease

c

The chemical bonds of carbohydrates and lipids have high potential energy because: A. They are strong oxidizing agents B. They are strong reducing agents C. Many of their bonds are C-C and C-H D. They are easy to hydrolyze E. Many of their bonds are C-O

c

What would happen to the strength of the proton gradient if NADH were abundant and ATP was being used at a constant rate? A) It would increase. B) It would decrease. C) It would not change.

c

Which of the following is NOT a product of cellular respiration? A) Carbon dioxide B) Water C) Oxygen D) ATP E) All of the above are produced in cellular respiration.

c

Which of the following is needed directly to produce both triose phosphates and RuBP? a) O2 b) NADPH c) ATP d) rubisco e) photosystem II

c

Which of the following is responsible for the transport of electrons between photosystem II and photosystem I? a) NADPH. b) NADP+. c) cytochrome b6f. d) water. e) chlorophyll.

c

Which one of the following statements about the formation of a peptide bond is INCORRECT? A) The reaction is endergonic B) The reaction is anabolic C) The reaction is spontaneous D) The reaction has a positive ΔG E) None of the above

c

During fermentation, pyruvate is: A. Hydrogenated B. Carboxylated C. Oxidized D. Reduced E. Phosphorylated

d

During pyruvate oxidation, pyruvate is broken down into CO2 and an acetyl group. The CO2 is: a) less oxidized than the acetyl group. b) more reduced than the acetyl group. c) more energetic than the acetyl group. d) less energetic than the acetyl group. e) None of the other answer options is correct.

d

Following the citrate cycle but before the electron transport chain and oxidative phosphorylation, most of the energy from the original glucose molecule is found in: A) Acetyl-CoA B) CO2 C) Pyruvate D) NADH E) ATP

d

For every six CO2 molecules incorporated into carbohydrate molecules, how many triose phosphates can be exported from the chloroplast? a) 6 b) 10 c) 12 d) 2 e) 1

d

How many CO2 molecules must enter the Calvin cycle to export three triose phosphates from the chloroplast? A. 1 B. 3 C. 6 D. 9 E. 12

d

Of the following molecules, which has the greatest potential energy? A) Water (H2O) B) Sodium chloride (NaCl) C) Carbon dioxide (CO2) D) Glucose (C6H12O6) E) Alanine (C3NH7O2)

d

Organisms with only one photosystem cannot: a) oxidize H2S. b) reduce CO2. c) reduce H2O. d) produce O2. e) reduce NADP+.

d

Which of the following best describes the benefit to early photosynthetic organisms gained by having two different photosystems in one cell? a) They produced oxygen. b) These organisms produced carbohydrates at twice the rate of organisms with a single photosystem. c) They could thrive in places where there was little or almost no light. d) They could use water as an electron donor

d

Which of the following compounds is required for the carboxylation step of the Calvin cycle? a) NADPH b) ATP c) 3-PGA d) RuBP e) ATP and NADPH

d

Which of the following would be directly altered as a result of a mutation that prevents photosystem II from functioning efficiently? A. The rate at which NADPH is produced B. The rate at which protons are transported into the thylakoid lumen C. The rate of ATP synthesis by ATP synthase in the chloroplast D. The amount of oxygen produced

d

Which step of the Calvin cycle would be affected first by a lack of NADPH? a) regeneration b) All of these choices are correct. c) carboxylation d) reduction

d

Why is the absorption and capture of light energy by chlorophyll molecules in plants more efficient than its absorption and capture by isolated chlorophyll molecules in the lab? A) Because the plant produces accessory pigments. B) Because the plant has a higher electron supply. C) Because an artificial light source is used in the lab. D) Because in the plant, the energy is transferred to another chlorophyll. E) Because the lab has a higher electron supply.

d

Paraquat is an herbicide that blocks the transfer of electrons from PS I to NADP+. Mechanistically, paraquat is an effective herbicide because it: A) Prevents the reduction of NADP+ B) Prevents the formation of reactive oxygen species C) Absorbs light energy that cannot be used for photosynthesis D) Increases cyclic electron transport, which does not produce NADPH E) Increases the formation of reactive oxygen species

e

A researcher is carrying out an experiment where she labels a protein with a fluorescent tag (so she can visualize its location in a cell), and introduces this tagged protein into the lumen of a single thylakoid. She observes her treated cells periodically, and notices that the labeled protein can move between grana, but is never observed in the stroma. What can she deduce? a) All thylakoid membranes and grana share a common lumen, through which the labeled protein can move. b) This protein can easily transfer between the inner and outer mitochondria membranes. c) This protein likely travels between different thylakoid membranes by moving through the stroma, but its movement through the stroma is very brief. d) This protein cannot easily diffuse through the thylakoid membrane. e) The protein likely travels through a common lumen shared by thylakoid membranes and grana, and cannot easily diffuse through the thylakoid membrane.

e

ATP production in photosynthesis requires: a) electrons. b) protons. c) light and protons. d) light. e) light, electrons, and protons.

e

After pyruvate oxidation, the chemical energy of how many carbons of the original glucose molecule is converted to chemical energy in the form of ATP in the remaining steps of cellular respiration? a) 3 b) 5 c) 2 d) 1 e) 4

e

After several weeks of no rain during the summer, you observe that leaves of some plants are wilted. Which of the following would you expect to observe at the cellular level with respect to photosynthesis? A) More glucose is going to be produced to compensate for the absence of water. B) The rate of electrons moving through the PETC will be greater than normal. C) More NADPH will be produced. D) More ATP will be synthesized by ATP synthase. E) The rate of the reduction of chlorophyll molecules will be decreased.

e

Glycolysis results in the partial oxidation of glucose to pyruvate. This means that: A) Glucose combines with oxygen in the cytoplasm to get partially oxidized. B) Glucose is broken down into ATP in the cytoplasm. C) Glucose donates electrons directly to NAD+. D) Glycolysis consists only of exergonic reactions so that ATP can be made form the release of energy. E) In the process of the conversion of glucose to pyruvate, some potential energy is transferred to NADH and ATP.

e

How does the metabolism occurring in chloroplasts differ from that of mitochondria? a) different electron sources b) different electron acceptors c) different proton sources d) None of the other answer options is correct. e) different electron acceptors and electron sources

e

How many molecules of NADPH are required for 12 molecules of RuBP to be carboxylated by rubisco? a) 10 b) 36 c) 24 d) 12 e) None of the other answer options is correct.

e

Imagine that you discover a carnivorous deep-sea fish that cannot utilize the carbon in carbonic acid (or any other inorganic molecule) present in seawater to form glucose (or other organic molecules). Living so far beneath the water's surface, this fish is also incapable of harnessing energy from the sun. This fish would be considered a: a) photoheterotroph. b) photoautotroph. c) phototroph. d) chemoautotroph. e) chemoheterotroph.

e

Of the following molecules, which has the greatest potential energy? a) sodium chloride b) water c) alanine d) carbon dioxide e) glucose

e

Photosystem I is a _____ than photosystem II. a) stronger oxidant and a stronger reductant b) stronger oxidant c) stronger reductant d) weaker oxidant e) weaker oxidant and a stronger reductant

e

Suppose a plant is exposed to a toxin that causes the thylakoid membranes to become much more permeable to protons than normal. Which of the following would be true? a) The carboxylation step of the Calvin cycle would be unaffected. b) The reduction step of the Calvin cycle would slow down and eventually stop. c) The carboxylation and reduction steps of the Calvin cycle would slow down and eventually stop. d) The regeneration step of the Calvin cycle would slow down and eventually stop. e) The reduction and regeneration steps of the Calvin cycle would slow down and eventually stop.

e

The chemical bonds of carbohydrates and lipids have high potential energy because: a) they are strong reducing agents. b) they are easy to hydrolyze. c) they are strong oxidizing agents. d) they are easy to phosphorylate. e) many of these bonds are C—C and C—H bonds.

e

Which molecule is oxidized during the photosynthetic reaction? A) CO2 B) C6H12O6 (glucose) C) NAD+ D) O2 E) H2O

e

Which of the following is/are rubisco substrates? a) O2 b) CO2 c) RuBP d) CO2 and RuBP e) CO2, O2, and RuBP

e

Which of the following organisms are considered heterotrophs? a) most bacteria b) dogs c) hydrogen bacteria d) plants e) most bacteria and dogs

e

Which of the following statements are true regarding pyruvate oxidation? a) This process occurs within the matrix of mitochondria. b) This process constitutes the second stage of cellular respiration. c) The process produces both CO2 and acetyl-CoA. d) The process yields no ATP via substrate-level phosphorylation. e) All of these choices are correct.

e

Which of the following statements is true regarding pyruvate and glucose? a) Glucose easily passes in and out of mitochondria, and can often be found in the mitochondrial matrix. b) Pyruvate is typically "trapped" in the intermembrane space of mitochondria, where it is oxidized to form acetyl-CoA. c) Glucose and pyruvate are remarkably similar in structure, with both molecules possessing a ring shape. d) Both glucose and pyruvate can feed directly into the citric acid cycle, although acetyl-CoA is the preferred reactant for this process. e) None of the other answer options is correct.

e

Which of the following statements is true regarding the Calvin cycle? a) The Calvin cycle is considered a "dark" reaction, because it is not directly related to photosynthesis. b) The Calvin cycle is a carefully regulated process because excess starch can be toxic to plant cells. c) The Calvin cycle uses a rare (and thus "rate-limiting") enzyme called rubisco. d) The action of rubisco is all that is necessary to produce high-energy triose phosphate from O2. e) None of the other answer options is correct.

e

Which of the following statements is true regarding the equation C6H12O6 + 6O2 →6CO2 + 6H2O + energy? a) The movement of hydrogen atoms in reactions involving C6H12O6 and H2O yields no information regarding the movement of electrons. b) The oxygen atoms in both CO2 and H2O are electronegative. c) Glucose could be considered a reducing agent. d) In the production of CO2 from glucose, the oxygen atoms lose electrons and the carbon atom is oxidized. e) The oxygen atoms in both CO2 and H2O are electronegative, and glucose is considered a reducing agent.

e

_______ bind to the active site of an enzyme. A) Substrates B) Competitive inhibitors C) Carbohydrates D) Uncompetitive inhibitors E) Substrates and competitive inhibitors

e

ATP is a nucleotide composed of adenine, _____, and three phosphate groups.

ribose