Microbiology Chapter 5, Microbiology Chapter 6/7

In Figure 7.2, the decimal reduction time (D value) for the culture is approximately 0 min. 15 min. 30 min. 45 min. 60 min.

15 min

In Table 7.1, which compound was the most effective against Staphylococcus? A B C D Can't tell

C

Which of the following substances is used for surgical hand scrubs? Phenol Chlorine bleach Chlorhexidine Soap Glutaraldehyde

Chlorhexidine

Which one of the following would you predict is an allosteric inhibitor of the Krebs cycle enzyme, -ketoglutarate dehydrogenase? Citric acid -ketoglutaric acid NAD+ NADH ADP

NADH

In Figure 5.8, the structure labeled (1) is NAD+. ATP synthase. Plasma membrane. Cell wall. Cytoplasm.

Plasma membrane.

Which of the graphs in Figure 5.5 best illustrates the activity of an enzyme that is saturated with substrate? a b c d e

c

Which statements are true? 1-Electron carriers are located at ribosomes. 2-ATP is a common intermediate between catabolic and anabolic pathways. 3-ATP is used for the long-term storage of energy and so is often found in storage granules. 4-Anaerobic organisms are capable of respiration. 5-ATP is generated by the flow of protons across the cell membrane. 2, 4, 5 1, 3, 4 2, 3, 5 1, 2, 3 All

2, 4, 5

Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours? 3 x 210 1024 243 48 16

3 x 210

Place the following surfactants in order from the most effective to the least effective antimicrobial activity: 1-Soap; 2-Acid-anionic detergent; 3-Quats. 1, 2, 3 1, 3, 2 2, 1, 3 3, 2, 1 3, 1, 2

3, 2, 1

Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample? 4 9 18 36 72

36

An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through? 64 32 6 5 4

5

In Figure 7.1, what is the thermal death time for culture (a)? 150°C 60 min. 120 min. 100°C Can't tell

60 min

In Figure 7.2, the thermal death time for this culture is 0 min. 10 min. 20 min. 40 min. 60 min.

60 min.

In Figure what is the thermal death time for culture (a)? 150°C 60 min. 120 min. 100°C Can't tell

60 min.

Most bacteria grow best at pH 1. 5. 7. 9. 14.

7

Which concentration of ethanol is the most effective bactericide? 100% 70% 50% 40% 30%

70%

In Figure 6.1, which line best depicts Neisseria gonorrhoeae when growing inside the human body? a b c

A

In Table 6.1, which medium (media) is (are) chemically defined? A B C A and B A and C

A

In Table, 6.1, in which medium would an autotroph grow? A B C A and B A and C

A

In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of 10% of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections? Bacterial cell walls in the water A biofilm in the reprocessor Contaminated disinfectant Fecal contamination of the bile ducts

A biofilm in the reprocessor

Which one of the following does NOT belong with the others? Acid-anionic detergents Benzoic acid Supercritical CO2 Pasteurization Peracetic acid

Acid-anionic detergents

The rates of O2 and glucose consumption by a bacterial culture are shown in Figure 5.6. Assume a bacterial culture was grown in a glucose medium without O2. Then O2 was added at the time marked X. The data indicate that These bacteria don't use O2. These bacteria get more energy anaerobically. Aerobic metabolism is more efficient than fermentation. These bacteria can't grow anaerobically.

Aerobic metabolism is more efficient than fermentation.

Which of the following substances is NOT effective against nonenveloped viruses? Alcohol Chlorine Ethylene oxide Ozone All are equally effective.

Alcohol

Which of the following pairs is mismatched? Ag - burns Alcohols - open wounds CuSO4 - algicide H2O2 - open wounds Organic acids - food preservation

Alcohols - open wounds

Which of the following affects the elimination of bacteria from an object? Number of bacteria present Temperature pH Presence of organic matter All of these

All of these

Which of the following is NOT a factor contributing to hospital-acquired infections? Some bacteria metabolize disinfectants. Gram-negative bacteria are often resistant to disinfectants. Invasive procedures can provide a portal of entry for bacteria. Bacteria may be present in commercial products such as mouthwash. All of these may contribute to hospital-acquired infection.

All of these may contribute to hospital-acquired infection.

Iodophors differ from iodine (I2) in that iodophors Don't stain. Are less irritating. Are longer lasting. Are combined with a nonionic detergent. All of these.

All of these.

A shipping company employee notices that the inside of ships' hulls where ballast water is stored are deteriorating. The hull paint contained cyanide to prevent microbial growth. Bacteria were growing on the hulls. You can therefore conclude that the Bacteria were using aerobic respiration. Bacteria were using anaerobic respiration. Bacteria were growing by fermentation. Bacteria were using cytochromes. Bacteria were photosynthetic.

Bacteria were growing by fermentation.

Table 7.2 The fate of E. coli O157:H7 in apple cider held at 8°C for 2 weeks, with and without preservatives, is shown below: In Table 7.2, which preservative is most effective? Sorbate Benzoate Sorbate + benzoate No preservative

Benzoate

Which of the following substances is NOT used to preserve foods? Biguanides Nisin Potassium sorbate Sodium nitrite Sodium propionate

Biguanides

Patients with indwelling catheters are susceptible to infections because Injected solutions are contaminated. Their immune systems are weakened. Infections can be transmitted from other people. Biofilms develop on catheters. Bacteria cause infections.

Biofilms develop on catheters.

Which of these disinfectants acts by denaturing proteins? Alcohols Aldehydes Bisphenols Halogens Phenolics

Bisphenols

Which of the following will NOT destroy prions? Boiling Incineration NaOH + autoclaving at 134°C Proteases All of these destroy prions.

Boiling

The addition of which of the following to a culture medium will neutralize acids? Buffers Sugars pH Heat Carbon

Buffers

A strictly fermentative bacterium produces energy By glycolysis only. By aerobic respiration only. By fermentation or aerobic respiration. Only in the absence of oxygen. Only in the presence of oxygen.

By glycolysis only.

In green and purple bacteria, electrons to reduce CO2 come from CO2. H2O. C6H12O6. Sunlight. Chlorophyll.

CO2.

In Table 7.1, which compound was bactericidal? A B C D Can't tell

Can't tell

In Table 7.1, which compound was the most effective against E. coli? A B C D Can't tell

Can't tell

In Table 7.3, which disinfectant was most effective against Salmonella? Doom K.O. Mortum Sterl Can't tell

Can't tell

In Figure 7.2, the thermal death point for this culture is 15 min. 50°C. 30 min. 170°C. Can't tell from the data provided.

Can't tell from the data provided.

Which of the following is a limitation of the autoclave? Requires a long time to achieve sterilization Cannot inactivate viruses Cannot kill endospores Cannot be used with heat-labile materials Cannot be used with glassware

Cannot be used with heat-labile materials

Which enzyme catalyzes the reaction: 2H2O2 2H2O + O2? Catalase Oxidase Peroxidase Superoxide dismutase

Catalase

Which of the following does NOT directly result from application of heat? Breaking of hydrogen bonds Breaking of sulfhydryl bonds Denaturing of enzymes Cell lysis Damage to nucleic acids

Cell lysis

Which of the following uses CO2 for carbon and H2 for energy? Chemoautotroph Chemoheterotroph Photoautotroph Photoheterotroph

Chemoautotroph

Which of the following uses glucose for carbon and energy? Chemoautotroph Chemoheterotroph Photoautotroph Photoheterotroph

Chemoheterotroph

Which of the following compounds is NOT an enzyme? Dehydrogenase Cellulase Coenzyme A -galactosidase Sucrase

Coenzyme A

An enzyme, citrate synthase, in the Krebs cycle is inhibited by ATP. This is an example of all of the following EXCEPT Allosteric inhibition. Competitive inhibition. Feedback inhibition. Noncompetitive inhibition. Beta oxidation.

Competitive inhibition.

A culture medium consisting of agar, human blood, and beef heart is a Chemically defined medium. Complex medium. Selective medium. Differential medium. Reducing medium

Complex medium.

Assume you are growing bacteria on a lipid medium that started at pH 7. The action of bacterial lipases should cause the pH of the medium to Increase. Decrease. Stay the same.

Decrease.

Which of the following is an advantage of the standard plate count? Can readily count cells that form aggregates Requires incubation time Determines the number of viable cells Chemical and physical requirements are determined by media and incubation. Cannot be used to count bacteria in food

Determines the number of viable cells

In Table 7.3, which disinfectant is the most effective at stopping bacterial growth? Doom K.O. Mortum Sterl Can't tell

Doom

Which of the following substances can sterilize? Alcohol Phenolics Ethylene oxide Chlorine Soap

Ethylene oxide

The data in Table 6.2 indicate that S. aureus is a(n) Mesophile. Facultative anaerobe. Facultative halophile. Aerobe. Halophile.

Facultative halophile.

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt? Psychrophiles Facultative halophiles Anaerobes Thermophiles Hyperthermophiles

Facultative halophiles

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper? Autoclave Gamma radiation Microwaves Sunlight Ultraviolet radiation

Gamma radiation

Which of the following is an example of a metabolic activity that could be used to measure microbial growth? Standard plate count Glucose consumption Direct microscopic count Turbidity MPN

Glucose consumption

Which of the following substances is NOT an oxidizing agent? Chlorine Glutaraldehyde Hydrogen peroxide Iodine Ozone

Glutaraldehyde

In noncyclic photophosphorylation, O2 is produced from CO2. H2O. C6H12O6. Sunlight. Chlorophyll.

H2O.

Which of the following is NOT used to disinfect water? Ozone Gamma radiation Chlorine Copper sulfate Heat

Heat

Which of the following will NOT inactivate endospores? Autoclave Chlorine dioxide High pressure Plasma Supercritical CO2

High pressure

Which one of the following does NOT belong with the others? Beta-propiolactone Glutaraldehyde Ethylene oxide Hydrogen peroxide Propylene oxide

Hydrogen peroxide

Salts and sugars work to preserve foods by creating a Depletion of nutrients. Hypotonic environment. Lower osmotic pressure. Hypertonic environment. Lower pH.

Hypertonic environment.

Which of the following statements about anaerobic respiration is false? It involves glycolysis only. It involves the Krebs cycle. It involves the reduction of nitrate. It generates ATP. It requires cytochromes.

It involves glycolysis only.

Which of the following statements about beta oxidation is false? It is a method of catabolizing fatty acids. It involves the formation of 2-carbon units. It involves the formation of acetyl-CoA. It is a step in glycolysis. It is used in petroleum degradation.

It is a step in glycolysis.

What is the fate of pyruvic acid in an organism that uses aerobic respiration? It is reduced to lactic acid. It is oxidized in the Krebs cycle. It is oxidized in the electron transport chain. It is catabolized in glycolysis. It is reduced in the Krebs cycle.

It is oxidized in the Krebs cycle.

Which of the following statements about photophosphorylation is false? Light liberates an electron from chlorophyll. The oxidation of carrier molecules releases energy. Energy from oxidation reactions is used to generate ATP from ADP. It requires CO2. It occurs in photosynthesizing cells.

It requires CO2.

How would a noncompetitive inhibitor interfere with a reaction involving the enzyme shown in Figure 5.3? It would bind to a. It would bind to b. It would bind to c. It would bind to d. Can't tell.

It would bind to b.

During which growth phase will gram-positive bacteria be most susceptible to penicillin? Lag phase Log phase Death phase Stationary phase The culture is equally susceptible during all phases.

Log phase

A urease test is used to identify Myobacterium tuberculosis because Urease is a sign of tuberculosis. M. tuberculosis produces urease. Urea accumulates during tuberculosis. Some bacteria reduce nitrate ion. M. bovis can cause tuberculosis.

M. tuberculosis produces urease.

Which of the following is the best method to sterilize heat-labile solutions? Dry heat Autoclave Membrane filtration Pasteurization Freezing

Membrane filtration

Which of the following is NOT a direct method to measure microbial growth? Direct microscopic count Standard plate count Filtration Metabolic activity MPN

Metabolic activity

Which of the following will NOT preserve foods? Desiccation High pressure Ionizing radiation Microwaves Osmotic pressure

Microwaves

In Table 7.3, which disinfectant was bactericidal? Doom K.O. Mortum Sterl Can't tell

Mortum

Which one of the following is most resistant to chemical biocides? Gram-negative bacteria Gram-positive bacteria Mycobacteria Protozoan cysts Viruses with lipid envelopes

Mycobacteria

Which compound is being reduced in the reaction shown in Figure 5.1? Isocitric acid and -ketoglutaric acid -ketoglutaric acid and NAD+ NAD+ NADH NADH and isocitric acid

NAD+

Which of the following is an organic growth factor? Glucose NAD+ Peptone NH4H2PO4 H2O

NAD+

Assume you are working for a chemical company and are responsible for growing a yeast culture that produces ethanol. The yeasts are growing well on the maltose medium but are not producing alcohol. What is the most likely explanation? The maltose is toxic. O2 is in the medium. Not enough protein is provided. The temperature is too low. The temperature is too high.

O2 is in the medium.

Gallionella bacteria can get energy from the reaction Fe2+ Fe3+. This reaction is an example of Oxidation. Reduction. Fermentation. Photophosphorylation. The Calvin-Benson cycle.

Oxidation

Which of the following does NOT achieve sterilization? Dry heat Pasteurization Autoclave Formaldehyde Ethylene oxide

Pasteurization

The source of nutrients in nutrient agar is Agar. Nutrient. Peptone and beef extract. Peptone and NaCl. All of these.

Peptone and beef extract.

Which enzyme catalyzes the reaction: H2O2 + 2H+ 2H2O? Catalase Oxidase Peroxidase Superoxide dismutase

Peroxidase

Which organism is NOT correctly matched to its energy source? Photoheterotroph - light Photoautotroph - CO2 Chemoautotroph - Fe2+ Chemoheterotroph - glucose Chemoautotroph - NH3

Photoautotroph - CO2

Cyanobacteria are a type of Chemoautotroph. Chemoheterotroph. Photoautotroph. Photoheterotroph.

Photoautotroph.

Which of the following has bacteriochlorophylls and uses alcohols for carbon? Chemoautotroph Chemoheterotroph Photoautotroph Photoheterotroph

Photoheterotroph

If you were preparing nutrient agar at home and didnt have an autoclave, what could you use to sterilize the nutrient agar? Bleach Boiling for 1 hour Hydrogen peroxide Oven at 121°C for 1 hour Pressure cooker at 121°C for 15 minutes

Pressure cooker at 121°C for 15 minutes

In Figure 5.8, the path labeled (2) is the flow of ____________ (arch over the top) Electrons. Protons. Energy. Water. Glucose.

Protons.

Which of the following is an advantage of the direct microscopic count? Can readily count organisms that are motile Enumerates dead cells Requires no incubation time Sample volume is unknown. Requires a large number of cells

Requires no incubation time

A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called a(n) Selective medium. Differential medium. Enrichment culture. Selective medium and Differential medium Differential medium and Enrichment culture

Selective medium and Differential medium

Glutaraldehyde is considered one of the most effective disinfectants for hospital use. Which of the following statements about glutaraldehyde is false? Stains and corrodes Is safe to transport Acts rapidly Is not hampered by organic material Attacks all microorganisms

Stains and corrodes

How is ATP generated in the reaction shown in Figure 5.4? Glycolysis Fermentation Photophosphorylation Oxidative phosphorylation Substrate-level phosphorylation

Substrate-level phosphorylation

Bone and tendons for transplant are decontaminated by Ethylene oxide. Glutaraldehyde. Peroxygens. Plasma sterilization. Supercritical fluids.

Supercritical fluids.

Which enzyme catalyzes the reaction: O2- + O2- + 2H+ H2O2 + O2? Catalase Oxidase Peroxidase Superoxide dismutase

Superoxide dismutase

Fatty acids are catabolized in The Krebs cycle. The electron transport chain. Glycolysis. The pentose phosphate pathway. The Entner Doudoroff pathway.

The Krebs cycle.

Which of the following best describes the pattern of microbial death? The cells in a population die at a constant rate. All the cells in a culture die at once. Not all of the cells in a culture are killed. The pattern varies depending on the antimicrobial agent. The pattern varies depending on the species.

The cells in a population die at a constant rate.

Which of the following is the best definition of oxidative phosphorylation? Electrons are passed through a series of carriers to O2. The energy released as carrier molecules are oxidized is used to generate ATP. The energy released in the reduction of carrier molecules is used to generate ATP. The transfer of a high-energy phosphate group to ADP.

The energy released as carrier molecules are oxidized is used to generate ATP.

The antimicrobial activity of chlorine is due to which of the following? The formation of hypochlorous acid The formation of hydrochloric acid The formation of ozone The formation of free O Disruption of the plasma membrane

The formation of hypochlorous acid

Which of the following is the best definition of generation time? The length of time needed for lag phase The length of time needed for a cell to divide The minimum rate of doubling The duration of log phase The time needed for nuclear division

The length of time needed for a cell to divide

Which of the following is the best definition of fermentation? The reduction of glucose to pyruvic acid The oxidation of glucose with organic molecules serving as electron acceptors The complete catabolism of glucose to CO2 and H2O The production of energy by substrate-level phosphorylation The production of ethanol from glucose

The oxidation of glucose with organic molecules serving as electron acceptors

Which of the following statements about substrate-level phosphorylation is false? It involves the direct transfer of a high-energy phosphate group from an intermediate metabolic compound to ADP. No final electron acceptor is required. It occurs in glycolysis. The oxidation of intermediate metabolic compounds releases energy that is used to generate ATP. It occurs in the Krebs cycle.

The oxidation of intermediate metabolic compounds releases energy that is used to generate ATP.

Assume you inoculated 100 cells into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 24 hours, you should have More cells in the 100 ml. More cells in the 200 ml. The same number of cells in both.

The same number of cells in both.

Which of the following pairs is mismatched? Psychrotroph - growth at 0°C Thermophile - growth at 37°C Mesophile - growth at 25°C Psychrophile - growth at 15°C Hyperthermophiles - growth at 100°C

Thermophile - growth at 37°C

Which of the following treatments is the most effective for controlling microbial growth? 63°C for 30 min. 72°C for 15 sec. 140°C for 4 sec. They are equivalent treatments. None is effective.

They are equivalent treatments.

Which is true about the reaction? glucose - ethanol This process requires O2. This process occurs anaerobically.

This process occurs anaerobically.

Which is true about the reaction? nitrate iron to nitrate iron This process requires O2. This process occurs anaerobically.

This process occurs anaerobically.

Which is true about the reaction? Ethanol - Acetic Acid This process requires O2. This process occurs anaerobically.

This process requires O2.

Which is true about the reaction? hydrogen ions to water by e coli This process requires O2. This process occurs anaerobically.

This process requires O2.

The advantage of the pentose phosphate pathway is that it produces all of the following EXCEPT Precursors for nucleic acids. Precursors for the synthesis of glucose. Three ATPs. NADPH. Precursors for the synthesis of amino acids.

Three ATPs.

What type of reaction is in Figure 5.2? Decarboxylation Transamination Dehydrogenation Oxidation Reduction

Transamination

Which of the following is NOT used to determine metabolic activity? Acid production from fermentation CO2 produced from the Krebs cycle NO2- produced from the electron transport chain Decreased dissolved oxygen Turbidity

Turbidity Turbidity

Which one of the following pairs is mismatched? Ionizing radiation - hydroxyl radicals Ozone - takes electrons from substances Plasma sterilization - free radicals Supercritical fluids - CO2 Ultraviolet radiation - desiccation

Ultraviolet radiation - desiccation

The term facultative anaerobe refers to an organism that Doesn't use oxygen but tolerates it. Is killed by oxygen. Uses oxygen or grows without oxygen. Requires less oxygen than is present in air. Prefers to grow without oxygen.

Uses oxygen or grows without oxygen.

A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The bacteria are most likely Fermenting the glucose. Oxidizing the glucose. Using the peptides. Not growing.

Using the peptides.

In Figure 6.1, which line best illustrates the growth of a facultative anaerobe incubated aerobically? a b c

a

What is the most acidic place in Figure 5.8? a b c d e

a

Figure 6.3 shows three containers of water connected by tubes. A selectively permeable membrane divides each tube. Solutes are added to each container to give final concentrations of 5% NaCl in (a); 10% NaCl in (b); and 5% sucrose in (c). When the experiment is first set up, the initial movement of water will be a to b; b to c; c to a. a to b; c to b; c to a. a to c; b to c; c to a. a to c; c to b; c to a. b to a; b to c; c to a.

a to b; c to b; c to a.

In Figure 6.1, which line best depicts a facultative anaerobe in the absence of O2? a b c

b

In Figure 6.1, which line best depicts a mesophile with an optimum temperature of 35 degrees incubated at 40 degrees a b c

b

In Figure 6.1, which line best depicts a psychrotroph incubated at 0°C? a b c

b

In Figure 6.1, which line best illustrates a mesophile at 5°C above its optimum temperature? a b c

b

In Figure 6.4, in which tube are facultative anaerobes growing? a b c d e

b

Micrococci are facultative halophiles. In Figure 6.1, which line best depicts the growth of Micrococcus luteus in a nutrient medium containing 7.5% NaCl? a b c

b

The graph at the left in Figure 5.7 shows the reaction rate for an enzyme at its optimum temperature. Which graph shows enzyme activity at a higher temperature? a b c d e

b

Which graph in Figure 7.3 best depicts the effect of placing the culture in an autoclave for 15 min. at time x? a b c d e

b

In Figure 6.2, which sections of the graph illustrate a logarithmic change in cell numbers? a and c b and d a and b c and d b only

b and d

In Table 7.2, which preservative is most effective? Sorbate Benzoate Sorbate + benzoate No preservative

benzoate

Assume that one culture is a freshly opened package of dried yeast with 0.1% moisture, another culture is the same yeast with 7.5% moisture, and the third culture is a package of yeast mixed with water. Each culture was exposed to 130°C in a hot-air oven. Which graph in Figure 7.1 most likely shows the yeast with 0.1% moisture? a b c a and b b and c

c

In Figure 6.1 ,which line best depicts an obligate anaerobe in the presence of O2? a b c

c

In Figure 6.1, which line best depicts a catalase-negative cell incubated aerobically? a b c

c

In Figure 6.1, which line best depicts a psychrophile incubated at room temperature? a b c

c

In Figure 6.1, which line shows the growth of an obligate aerobe incubated anaerobically? a b c

c

In Figure 6.2, which section shows a growth phase where the number of cells dying equals the number of cells dividing? a b c d a and c

c

Assume 109 E. coli cells/ml are in a flask. Which graph in Figure 7.3 best depicts the effect of placing the culture at 7°C at time x? a b c d e

d

Refer to Figure 5.8. In aerobic respiration, where is water formed? a b c d e

d

In Figure 5.8, where is ATP produced? a b c d e

e

In Figure 6.4, in which tube are microaerophiles growing? a b c d e

e

Beggiatoa bacteria get energy by oxidizing S2- to S6+. This means they take ________ for their ________. electrons; electron transport chain electrons; fermentation protons; NAD+ sulfur; photophosphorylation glucose; glycolysis

electrons; electron transport chain

Which of the following is NOT necessary for respiration? Cytochromes Flavoproteins A source of electrons Oxygen Quinones

oxygen