Chapter 6 test microbio
41) Glycolysis A) requires oxygen. B) may occur under aerobic or anaerobic conditions. C) produces 3 ATP molecules per molecule glucose. D) produces 4 molecules of NAD per molecule glucose. E) always occurs under aerobic conditions.
B
39) The term "precursor metabolite" refers to molecules that A) activate cell components. B) are used in biosynthesis. C) result from cell activities. D) are present but inactive. E) denature enzymes.
B
85) You tell your patient's parents that muscle weakness is frequently a sign of mitochondrial disease because A) muscle cells require a lot of energy, which is provided by the many mitochondria within these cells. B) muscles require a lot of energy which is provided by the mitochondrial DNA of the red blood cells. C) people with mitochondrial disease seldom eat sufficient protein to fuel the mitochondria. D) the diseased mitochondria release toxins into the muscles of the affected people, weakening them. E) the diseased mitochondria consume all the energy that is supposed to be directed to the muscle cells.
A
12) The name given to the reaction involving removal of electrons or hydrogen atoms from a compound is A) glycolysis. B) oxidation. C) reduction. D) metabolism. E) respiration.
B
18) Oxygen serves as the terminal electron acceptor in A) fermentation. B) aerobic respiration. C) anaerobic respiration. D) reduction. E) oxidation.
B
19) The terminal electron acceptor in respiration may be A) NAD, oxygen, OR nitrate. B) oxygen, nitrate, OR an inorganic molecule. C) NAD, nitrate, OR an inorganic molecule. D) NAD, water, OR an inorganic molecule. E) an inorganic molecule, water, OR oxygen.
B
2) Studies done by Buchner showed that ground-up yeast cells were able to convert sugar to alcohol. The components of the mixture that were responsible for this transformation were A) DNA molecules. B) enzymes. C) lipids. D) carbohydrates. E) phospholipids.
B
25) Enzymes act as A) substrates. B) catalysts. C) products. D) catabolites. E) reducters.
B
84) You explain to the child's parents that the role of the mitochondria is A) to transport proteins to the cytoplasmic membrane. B) to produce the energy currency, ATP, for a cell. C) to break down toxins in the body. D) to initiate DNA replication during cell division. E) to protect the body from bacterial invaders.
B
83) An atom that has a lower affinity for electrons than another is ________ than the other. A) more electronegative B) less electronegative C) equally electronegative D) more electropositive E) less electropositive
A
1) Experiments designed by ________ suggested that living cells caused the fermentation of sugar to produce alcohol. A) Pasteur B) Koch C) Wohler D) Fleming E) Jenner
A
13) The name given to the reaction involving addition of electrons or hydrogen atoms to a compound is A) reduction. B) glycolysis. C) oxidation. D) metabolism. E) respiration.
A
14) NAD in its reduced form is symbolized as A) NADH. B) NAD. C) NAD−. D) NADP. E) NADP+.
A
16) Glycolysis, the Entner-Duodoroff pathway, and the pentose phosphate pathway all produce A) pyruvate. B) NAD. C) NADP. D) acetyl-CoA. E) pyrite.
A
17) Cells degrade sugar largely to A) gain energy. B) use energy. C) convert fat to energy. D) use coenzymes. E) generate pyruvate.
A
31) Feedback inhibition A) is a way of regulating the amount of product produced. B) rarely involves the use of allosteric enzymes. C) involves inhibiting the last of a series of reactions. D) results in raising the activation energy for the reaction. E) is only observed in bacteria.
A
47) Which type of phosphorylation does not require a membrane? A) Substrate-level phosphorylation B) Oxidative phosphorylation C) Photophosphorylation D) All types of phosphorylation require a membrane. E) Phosphorylation never requires a membrane.
A
49) Proton motive force A) is used to synthesize ATP. B) is used to synthesize ADP. C) is used to produce NADH. D) is used to produce FADH2. E) uses ADP and ATP.
A
65) How would cellulose-degrading bacteria in the rumen (stomachs) of a cow benefit the animal? A) The bacteria would produce, secrete, and incorporate organic molecules as they obtain energy from the cellulose in grass and replicate. The cow could then digest both the secreted organic molecules AND the bacteria that synthesized them. B) The bacteria would produce sugars as they digested the cellulose. These sugars would be given off to the cow as a symbiotic relationship in exchange for the protected location of the stomachs of the cow for the bacteria to grow and replicate in. C) They wouldn't benefit the animal - they would replicate and cause disease in the animal, leading to its death. D) They wouldn't benefit the animal but they would benefit the other bacteria within the animal. This is why cows must have food sources other than grass in order to survive. E) They are needed to break down endospores of potential pathogens that are certain to cause illness or even death in the cow if it consumes them when it eats grass.
A
68) Chemolithotrophs near hydrothermal vents support a variety of life forms. Why is this analogous to photosynthetic microbes supporting life forms closer to the surface of the planet? A) Because all life forms need some energy source, electron source, and carbon source. Chemolithotrophs fix inorganic carbon and, if consumed by other microbes, could serve as sources for all three requirements for life. This is very similar to the role that photosynthetic microbes play in the top levels of the oceans/lakes. B) Because chemolithotrophs will also use energy from sunlight to form their sugars/get their chemical energy...much like photosynthetic microbes. C) Because chemolithotrophs also pull in carbon dioxide as their carbon source, just like photosynthetic microbes. D) Because photosynthetic microbes use heat energy from the sun as an energy source. Chemolithotrophs use heat energy from hydrothermal vents, but it's still heat energy. This makes both microbes similar. E) Because chemolithotrophs are also photosynthetic. They use the thermal energy from the vent to generate glucose from the ocean water around them. This glucose is then used by all the other organisms in the environment to support their growth.
A
8) Free energy A) is the amount of energy gained by breaking bonds of a chemical. B) includes the energy lost as heat. C) differs for a given reaction depending on the number of steps involved. D) always results in a decrease in total energy. E) is the amount of energy lost by breaking bonds of a chemical.
A
80) Which enzyme drives ATP synthesis in respiration? A) ATP synthase B) ADP phosphorylase C) Proton movase D) Oxidoreductase E) ATP dehydrogenase
A
91) Why was it necessary for the lab to inoculate a sample of the incubated tetrathionate broth onto a medium selective for Salmonella? A) To confirm that the bacteria in the broth is Salmonella and not another bacterial species. B) To confirm that the bacteria in the broth is E. coli and not another bacterial species. C) To check whether the Salmonella has the ability to form endospores. D) To confirm that Salmonella is a bacterium and not a virus or protozoan. E) To confirm that Salmonella is a facultative anaerobe and not an obligate acidophile.
A
20) Which of the following processes generates the greatest amount of energy? A) Fermentation B) Aerobic respiration C) Krebs cycle D) Glycolysis E) Phosphorylation
B
21) Fermentation A) uses an inorganic molecule as the final electron acceptor. B) uses an organic molecule as the final electron acceptor. C) results in the production of a large amount of ATP. D) is necessary in some organisms to produce reduced electron carriers. E) uses an organic molecule as the final electron acceptor AND is necessary in some organisms to produce reduced electron carriers.
B
23) Pyruvate can be metabolized along two major routes. They are A) oxidation and reduction. B) fermentation and respiration. C) metabolism and anabolism. D) anabolism and catabolism. E) fermentation and oxidation.
B
26) Enzymes act on ________ to generate ________. A) products, catabolites B) substrates, products C) products, substrates D) glucose, anabolites E) ATP, glucose
B
28) The mutual interaction of substrate and enzyme is described as a(n) A) lock and key arrangement. B) induced fit. C) active site. D) allosteric site. E) active site AND allosteric site.
B
29) Most enzymes A) are generic, typically recognizing a number of different substrates. B) are specific, typically recognizing a single or a few substrates. C) are active over a wide pH range. D) are active over a wide temperature range. E) are unaffected by heat or acidity
B
33) The small, non-protein molecules that can be readily separated from an enzyme and are responsible for transfer of atoms from one molecule to another are referred to as A) vitamins. B) coenzymes. C) enzymes. D) hormones. E) active sites.
B
48) In the electron transport system A) NADH and FADH2 both donate electrons at the same location. B) NADH donates electrons "upstream" of where FADH2 donates electrons. C) NAD donates electrons at the head of the chain. D) NADP donates electrons in the middle of the chain. E) NADP removes electrons in the middle of the chain
B
5) Energy is defined as A) water flowing up a dam. B) the capacity to do work. C) the use of high-level phosphate bonds. D) the potential to fall. E) the result of work.
B
50) In the phototrophic production of energy, the oxygen originates from A) carbon dioxide. B) water. C) glucose. D) hydrogen peroxide. E) sulfates.
B
52) The sugar component of RNA and DNA nucleotides is synthesized A) as deoxyribose and then changed to ribose. B) as ribose and then changed to deoxyribose. C) as ribose and then changed to riboxy. D) using the Calvin cycle. E) as deoxyribose and then changed to deboxy.
B
6) Biosynthetic reactions that require energy for the conversion of molecular subunits into larger molecules are called A) kinetic energy. B) anabolic reactions. C) catabolic reactions. D) precursor molecules. E) canabolic reactions
B
69) The linking of N-acetyleglucosamine, N-acetylemuramic acid, and tetrapeptides is a(n) ________ reaction that ________ ATP. A) catabolic; releases B) anabolic; requires C) fermentation; releases D) catabolic; requires E) degradation; releases
B
7) Exergonic reactions A) occur when there is more free energy in the products than the reactants. B) occur when there is more free energy in the reactants than the products. C) are defined as a decrease in entropy. D) are chemoorganotrophic. E) are defined as a decrease in energy AND are chemoorganotrophic.
B
70) Please select the TRUE statement regarding metabolic processes. A) Anabolic processes degrade subunits of macromolecules, using ATP and precursor metabolites. B) Catabolic processes harvest the energy released during breakdown of compounds to synthesize ATP. C) Anabolic processes assemble subunits of macromolecules, releasing ATP and precursor metabolites. D) Catabolic processes harvest the energy released during synthesis of compounds to break down ATP. E) Anabolic and catabolic processes have no relation to each other; they function completely independently.
B
71) Please identify the TRUE statement. A) Exergonic reactions consume energy because the starting compounds have less free energy than the products. B) "Substrate" refers to a substance on which an enzyme acts to form products OR a surface on which an organism can grow. C) A terminal electron acceptor is a chemical that is ultimately oxidized as a consequence of fermentation or respiration. D) Aerobic respiration is a metabolic process in which electrons are transferred from the electron transport chain to an organic intermediate. E) Activation energy is the energy required to create a bond in a chemical reaction.
B
73) Your brother has a bacterial infection. He tells you he going to the gym where he plans to sit in the sauna for an hour. He thinks that this will cure his infection, because the heat in the sauna will denature the enzymes of the bacteria making him ill. You are a nursing student who is currently studying microbiology. You tell him that A) his plan is sure to work because pathogens are mesophiles, so their enzymes will definitely become denatured and stop working. B) his plan won't work; homeostasis will keep his body temperature constant even in the sauna, so the bacteria (and his normal microbiota and body cells) will not be impacted. C) his plan will work because his body temperature will likely rise to about 60oC in the sauna, which is enough to denature the pathogen's enzymes. D) his plan will work; the organism causing his illness will likely dehydrate and be killed in the sauna but he is probably going to contract a different pathogen in that environment. E) his plan won't work; most pathogens are thermophiles so the temperature of the sauna will not affect the enzymes of the organism causing his illness.
B
Your patient has just returned from vacation in Asia. She has come to the clinic where you work, complaining of abdominal pain, fever, diarrhea, and nausea. She reports that the last day of her trip included a visit to a turtle sanctuary, where tourists have an opportunity to handle rescued turtles. You suspect that your patient has salmonellosis, caused the the bacterium Salmonella enterica. You get a stool sample from the patient and send it to the lab for analysis. There, your patient's stool sample is inoculated into tetrathionate broth and incubated overnight. The lab reports that the broth is turbid after incubation, indicating bacterial growth. A sample is inoculated onto an agar plate designed to isolate S. enterica and after 24 hours of aerobic incubation, colonies of suspected S. enterica are seen. Further tests confirm S. enterica, supporting your presumptive diagnosis 88) Tetrathionate broth is a selective, enrichment medium for S. enterica. What does this mean? A) This is a medium that encourages the growth of normal microbiota and reduces the growth of S. enterica. B) This is a medium that inhibits the growth of some bacteria and enhances the growth of S. enterica. C) This is a medium that inhibits the growth of some bacteria and in which S. enterica colonies exhibit an identifiable color. D) This is a medium that facilitates the growth of all bacteria but enhances the growth of S. enterica. E) This is a medium that facilitates the growth of all bacteria but in which S. enterica exhibits a noticeable color.
B
10) The readily usable energy currency of cells is A) electricity. B) the electron transport system. C) ATP. D) CTP. E) the electron transport system AND CTP.
C
11) Each of the following statements about chemoorganotrophs is true EXCEPT A) they may use substrate-level phosphorylation to produce ATP. B) they may use oxidative phosphorylation to produce ATP. C) they may use photophosphorylation to produce ATP. D) they obtain energy by degrading organic compounds. E) they generally rely on the metabolic activities of photosynthetic organisms.
C
24) The use of the suffix "ase" on a word denotes a(n) A) substrate. B) product. C) enzyme. D) electron acceptor. E) substrate AND electron acceptor.
C
3) Which of the statements about catabolism and anabolism is TRUE? A) They refer only to the reactions dealing involved in the metabolism of lipids. B) The intermediates of catabolism serve as products in anabolism. C) The energy gathered during catabolism is used during anabolism. D) They refer only to the reactions involved in carbohydrate synthesis. E) The energy gathered during anabolism is used during catabolism.
C
30) Allosteric enzymes A) may bind two substrates at the same time. B) are used to bind to other enzymes. C) have an additional binding site that is involved in regulating enzyme activity. D) are twice as fast as single-site enzymes. E) have an additional binding site that is never involved in regulating enzyme activity.
C
36) Most enzymes function best at A) acidic pH and high salt concentrations. B) basic pH and low salt concentrations. C) slightly above pH 7 and low salt concentrations. D) neutral pH and high salt concentrations. E) slightly above pH 7 and high salt concentrations.
C
37) Which is true of competitive inhibition? A) It involves an allosteric enzyme. B) Substrate and inhibitor bind to different active sites. C) A sulfa antibiotic is a competitive inhibitor. D) Mercury is a competitive inhibitor. E) Inhibitor permanently changes active site shape
C
42) The energy yield of any energy-transforming pathway A) is always fixed, despite the removal of precursor metabolites for biosynthesis. B) is variable depending on the type of enzymes used. C) is variable depending on the amount of precursor metabolites removed for biosynthesis. D) is fixed by the amount of oxygen available. E) is fixed by the amount of carbon dioxide available.
C
43) The transition step A) links glycolysis to the pentose phosphate pathway. B) links the pentose phosphate pathway to the electron transport chain. C) links glycolysis to the TCA cycle. D) takes place in the matrix of the nucleus. E) links the TCA cycle to fermentation.
C
44) The TCA cycle produces A) ATP, FAD, and precursor metabolites B) NADH, ATP, and FAD. C) FADH2, NADH, and precursor metabolites. D) FADH2, ADP, and NADH. E) precursor metabolites, NAD, and FADH2.
C
45) What happens to the carbon molecules in the pyruvic acid that goes through the TCA cycle? A) They get incorporated into cell material. B) They are excreted as waste organic acids. C) They become carbon dioxide. D) They form "energy storage molecules" for the cell. E) They become phosphorylated.
C
46) The electron transport system A) requires a membrane AND requires mitochondria and ribosomes. B) uses the nuclear membrane of eukaryotes AND generates a concentration gradient of protons. C) requires a membrane AND generates a concentration gradient of protons. D) uses the mitochondrial membrane of prokaryotes AND generates a concentration gradient of protons. E) requires mitochondria and ribosomes AND generates a concentration gradient of protons.
C
51) Anoxygenic photosynthetic bacteria A) obtain electrons from water. B) produce oxygen as a by-product. C) may obtain electrons from H2S. D) are obligate aerobes. E) produce oxygen as a by-product AND may obtain electrons from H2S.
C
63) Fermentation is sometimes used as a means of slowing food spoilage. Why would fermentation lead to this outcome? A) Fermentation is THE process that directly reduces sugars in food. Without sugars, bacteria cannot grow and spoil the food. B) Fermentation will lead to production of high levels of ethanol (95% or higher)—ethanol will kill bacteria. C) Fermentation will lead to production of acidic by-products, dropping the pH of the food below a level that bacteria can tolerate. D) This is a trick question—fermentation actually IS food spoilage and cannot be used to prevent it under any circumstances. E) Fermentation will lead to production of acidic by-products, raising the pH of the food above a level that bacteria can tolerate.
C
64) Why would a cell ferment rather than respire? A) There's no oxygen present, and it cannot respire anaerobically. B) It lacks the ability to respire (i.e. no electron transport chain). C) There is no oxygen present and it cannot use anaerobic respiration OR it lacks the ability to respire (i.e., no electron transport chain). D) More ATP is produced for the cell by fermentation than by aerobic respiration. E) There is too much oxygen available and fermentation is a safer alternative.
C
66) A worker in a cheese-making facility argued that whey, a nutrient-rich by-product of the process, should be dumped into a nearby pond to serve as fish food. Is this a good idea or a bad one, and why? A) It's a great idea! Let's feed the fish and help them multiply! In fact, other organisms could also benefit from this approach. B) Bad idea—the fish won't be able to eat the whey, so it will sit there rotting and pollute the waters, making them uninhabitable for the fish. C) Bad idea—bacteria would thrive on this rich nutrient source and multiply, using the oxygen in the water to harvest the energy from the whey. Without the oxygen, the fish will die. D) Great idea! This will not only feed the fish, but also microbes and other small organisms. It'll enhance the entire food chain and help all of them! E) Bad idea—whey stimulates the growth of any pathogenic bacteria in water; these pathogens will then infect and kill all the fish in the pond.
C
67) A student argued that aerobic and anaerobic respiration should produce the same amount of energy. He argued that both processes are essentially the same—only the terminal electron acceptor is different. What's wrong with his argument? A) Nothing—they SHOULD both produce the same amount of energy. Clearly he knows more than his professors or the writers of his textbook. B) Not all electrons are brought into the electron transport chain with the same amounts of potential energy. NADH, for example, enters the electron transport chain "further up" than FADH2—so it will lead to less proton motive force being generated, and thus less eventual ATP. C) Not all electron acceptors are the same—some are closer in terms of electronegativity to their high-energy electron carrier molecules (e.g., NADH) than others, and this impacts the amount of produced energy. Oxygen has the highest electron affinity of the terminal electron acceptors used. D) He should believe what his instructors tell him, without question—and they say aerobic respiration is better, so it MUST be so.
C
72) What is the effect of poisons such as mercury in antimicrobial products? Recall that mercury oxidizes the S-H groups of the amino acid cysteine in proteins, converting it to cystine. A) Competitive inhibition—the mercury binds to the active site of a bacterial enzyme, inhibiting the function of the enzyme. B) Reversible non-competitive inhibition—the mercury binds to an allosteric site on a bacterial enzyme, changing the active site shape temporarily and inhibiting enzyme function. C) Irreversible non-competitive inhibition—the mercury binds to an allosteric site on the enzyme and permanently changes the shape of the active site, so that the enzyme becomes nonfunctional. D) Reversible non-competitive inhibition—the mercury binds to the active site of an enzyme temporarily, inhibiting its function. E) Competitive inhibition—the mercury binds to an allosteric site on a bacterial enzyme, blocking attachment of the appropriate substrate and inhibiting the function of the enzyme.
C
76) Which is FALSE regarding glycolysis? A) It yields ATP. B) It is an anaerobic process. C) The end product is acetyl-CoA. D) It occurs during fermentation. E) ATP is used.
C
79) Which pair is correctly matched, regarding electron transport carriers in eukaryotes? A) Complex I - succinate dehydrogenase complex B) Complex II - cytochrome c oxidase complex C) Complex III - cytochrome bc1 complex D) Complex IV - NADH dehydrogenase complex E) None of the answer choices is correct.
C
81) Which of the following is NOT common to aerobic respiration, anaerobic respiration, AND fermentation? A) Breakdown of glucose B) Generation of ATP C) Electron transport chain D) Reduction of NAD E) Production of pyruvate
C
89) Tetrathionate is an oxidized form of sulfur that can act as a terminal electron acceptor. What does the fact that S. enterica can grow in this medium this tell you about this organism? A) It is an obligate aerobe. B) It is an obligate anaerobe. C) It is a facultative anaerobe. D) It is Gram negative. E) It has a capsule.
C
15) The most common starting pathway for the breakdown of sugars is A) respiration. B) fermentation. C) oxidation. D) glycolysis. E) anabolism.
D
27) Enzymes speed up reactions by A) raising activation energy. B) producing heat. C) reducing entropy. D) lowering activation energy. E) electron carriers.
D
32) Coenzymes are derivatives of A) minerals. B) proteins. C) lipids. D) vitamins. E) enzymes.
D
35) Environmental factors that may affect enzyme activity include A) temperature. B) pH. C) salt. D) temperature, pH, AND salt. E) None of the answer choices is correct.
D
4) The general term used to describe the anabolic and catabolic reactions in a cell is A) enzymatic. B) thematic. C) aerobic respiration. D) metabolism. E) canabolism.
D
40) Which is true regarding the three central metabolic pathways? A) They form high-energy bonds that can be used to synthesize ATP. B) They form intermediates that can be oxidized to generate reducing power. C) They form precursor metabolites. D) All of the answer choices are correct. E) None of the answer choices is correct.
D
74) Which of the following produces the most precursor metabolites? A) Fermentation B) TCA cycle C) Pentose phosphate pathway D) Glycolysis E) Transition step
D
75) Please select the FALSE statement regarding the central metabolic pathways. A) Glycolysis oxidizes glucose to pyruvate, yielding some ATP and NADH, and six different precursor metabolites. B) The pentose phosphate pathway oxidizes glucose, producing two different precursor metabolites and NADPH for biosynthesis. C) The transition step and TCA cycle complete the oxidation of glucose, yielding ATP, reducing power, and three different precursor metabolites. D) The transition step and TCA cycle are repeated four times to yield ATP, reducing power, and three different precursor metabolites. E) Two molecules of acetyl-CoA are generated for each glucose molecule that enters glycolysis, so the breakdown of one molecule of glucose causes the TCA cycle to turn twice.
D
78) The electron transport chain is a group of membrane-embedded carriers that pass electrons from one to the next, while simultaneously pumping ________ across the membrane, generating a(n) ________. A) glucose; proton motive force B) hydrogen ions; electron gradient C) electrons; ATP gradient D) hydrogen ions; proton motive force E) protons; electron motive force
D
86) The cellular process directly impacted in muscle cells of people with mitochondrial disease is A) protein synthesis. B) DNA replication. C) transcription. D) aerobic respiration. E) fermentation.
D
87) Your patient's parents ask you why their child's mitochondria do not function properly. You explain that one explanation is that mitochondria contain their own ________, which may contain mistakes called ________, resulting in insufficient mitochondrial activity. A) DNA; missense B) plasmids; mutations C) normal microbiota; mutations D) DNA; mutations E) proteins; mismatches
D
9) Bacteria that can absorb light energy and convert it into ATP are commonly called A) cytotrophs. B) metatrophs. C) chemotrophs. D) phototrophs. E) cytochromes AND chemotrophs.
D
90) Tetrathionate broth is an enrichment medium. Initially, when a mixed bacterial stool sample is inoculated into this medium, the bacteria respire aerobically. Once O2 is depleted, most bacteria switch to fermentation in order to continue growth. However, Salmonella can use the tetrathionate in this medium as a terminal electron acceptor, so can grow anaerobically. Why does this give the bacteria a competitive advantage over other bacteria in the sample? A) Tetrathionate inhibits the growth of fermenters. B) Fermentation yields more ATP than aerobic respiration. C) Anaerobic respiration yields more ATP than aerobic respiration. D) Anaerobic respiration yields more ATP than fermentation. E) Tetrathionate yields more ATP than glucose.
D
22) Which is (are) true regarding organic acids? A) They are weak acids. B) They are often involved in metabolic reactions. C) They often exist in the ionized form at the near-neutral pH found in a cell. D) Pyruvate and pyruvic acid refer to different forms of the same substance. E) All of the answer choices are true.
E
34) Which is (are) true of coenzymes? A) They are organic molecules. B) They transfer atoms from one molecule to another. C) They may bind to a number of different enzymes. D) They are synthesized from vitamins. E) All of the answer choices are correct.
E
38) Mercury in mercurochrome inhibits growth A) through competitive inhibition. B) through a reversible action. C) by oxidizing the sulfhydryl groups in cysteine. D) by changing the shape of proteins. E) by oxidizing the sulfhydryl groups in cysteine AND by changing the shape of proteins.
E
82) Heart muscle is damaged after a heart attack (MI) because blood flow to the heart is stopped. A researcher injected cyanobacteria into the damaged hearts of test animals that has been given MIs. The animals' conditions improved after the procedure, but not significantly. The researcher repeated the experiment, this time illuminating the cyanobacteria with high intensity light after injecting the cells into the damaged hearts. Now the animals did much better, recovering well from their heart attacks. Which of the following explains this outcome? A) Cyanobacteria have the capacity to carry blood. Illuminating the cells increases their ability to transport blood into the damage heart muscle. B) Cyanobacteria produce alcohol through photosynthesis, and this stimulates the heart cells. Illuminating the bacteria increases this reaction. C) Illuminated cyanobacteria multiply rapidly; the expanding mass of cells dilates blood vessels to the heart, bringing more nutrients and oxygen to the heart cells. D) Illuminated cyanobacteria produce carbon dioxide by photosynthesis. Illumination increases the amount of released CO2 that the heart cells then use for anaerobic respiration. E) Cyanobacteria produce oxygen by photosynthesis. Illuminating the cells increases amount of O2 released that is then used by heart cells for aerobic respiration.
E
92) Degradation of fats as an energy source involves all of the following except A) β-oxidation. B) acetyl-CoA. C) glycerol. D) lipase. E) transamination.
E
53) The change in free energy of a reaction varies T or F
F
55) Enzymes are changed by the reaction as they raise the activation energy. T or F
F
56) Competitive inhibition usually involves both substrate and inhibitor competing for binding at the allosteric site. T or F
F
59) The terminal electron acceptor in aerobic respiration is water, which is broken down to hydrogen and oxygen T or F
F
62) The Calvin cycle produces six ATP for every six turns of the cycle T or F
F
77) In Gram-negative bacteria, the electron transport chain involved in respiration is located in the lipopolysaccharide layer. T or F
F
54) Both glycolysis and the pentose phosphate pathway oxidize glucose to pyruvate. T or F
T
57) The production of ATP via the electron transport system, in either eukaryotes or prokaryotes, requires the use of a membrane. T or F
T
58) The TCA cycle must "turn twice" in order to complete the oxidation of one glucose molecule. T or F
T
60) In fermentation, the only ATP produced was during glycolysis and the fermentation reactions usually result in converting NADH to NAD. T or F
T
61) H2S and NH3 may be used by some prokaryotes as energy sources. T or F
T
93) Cells must secrete enzymes that degrade macromolecules into their subunits before they can use these compounds. T or F
T
