Which enzyme catalyzes the reaction: H2O2 + 2H+ --> 2H2O?

Most bacteria grow best at pH

Which of the following pairs is mismatched?

Salts and sugars work to preserve foods by creating a

Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours?

Patients with indwelling catheters are susceptible to infections because

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?

Which of the following is NOT a direct method to measure microbial growth?

A culture medium consisting of agar, human blood, and beef heart is a

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

Which of the following is an organic growth factor?

Which of the following is NOT used to determine metabolic activity?

Which concentration of ethanol is the most effective bactericide?

Which of the following affects the elimination of bacteria from an object?

Which of the following substances is used for surgical hand scrubs?

Which of the following will NOT inactivate endospores?

Which of the following pairs is mismatched?

Which of the following is NOT a factor contributing to hospital-acquired infections?

Which of the following treatments is the most effective for controlling microbial growth?

Which of the following substances is NOT an oxidizing agent?

Bone and tendons for transplant are decontaminated by

Which of the following substances is NOT used to preserve foods?

Which one of the following is most resistant to chemical biocides?

Which of the following does NOT achieve sterilization?

Which of the following best describes the pattern of microbial death?

Glutaraldehyde is considered one of the most effective disinfectants for hospital use. Which of the following statements about glutaraldehyde is false?

Which of the following is NOT used to disinfect water?

Which of the following is a limitation of the autoclave?

Which of the following is the best method to sterilize heat-labile solutions?

Which enzyme catalyzes the reaction: O2- + O2- + 2H+ --> H2O2 + O2?

During which growth phase will gram-positive bacteria be most susceptible to penicillin?

Which of the following is the best definition of generation time?

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?

Which enzyme catalyzes the reaction: 2H2O2 --> 2H2O + O2?

The source of nutrients in nutrient agar is

Which of the following is an advantage of the standard plate count?

Which of the following does NOT directly result from application of heat?

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?

Which of these disinfectants acts by denaturing proteins?

Which of the following substances is NOT effective against nonenveloped viruses?

If you were preparing nutrient agar at home and didn't have an autoclave, what could you use to sterilize the nutrient agar?

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

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

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?

In Figure 6.2, which sections of the graph illustrate a logarithmic change in cell numbers?

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

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

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?

In Figure 6.4, in which tube are facultative anaerobes growing?

In Figure 6.4, in which tube are microaerophiles growing?

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

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

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

In Figure 6.1, which line best depicts a mesophile with an optimum temperature of 35°C incubated at 40°C?

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

In Table, 6.1, in which medium would an autotroph grow?

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?

In Table 7.1, which compound was the most effective against Staphylococcus?

In Figure 7.2, the decimal reduction time (D value) for the culture is approximately

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?

In Table 7.1, which compound was the most effective against E. coli?

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

In Table 7.3, which disinfectant is the most effective at stopping bacterial growth?

In Figure 7.2, the thermal death point for this culture is

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

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

The data in Table 6.2 indicate that S. aureus is a(n)

In Table 7.3, which disinfectant was most effective against Salmonella?

In Table 7.1, which compound was bactericidal?

In Figure 7.2, the thermal death time for this culture is

In Table 7.2, which preservative is most effective?

In Table 7.3, which disinfectant was bactericidal?

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?

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

Which one of the following does NOT belong with the others?

Which one of the following does NOT belong with the others?

Which of the following will NOT preserve foods?

The antimicrobial activity of chlorine is due to which of the following?

Which one of the following pairs is mismatched?

In Table 6.1, which medium (media) is (are) chemically defined?

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

Which of the following is an advantage of the direct microscopic count?

Iodophors differ from iodine (I₂) in that iodophors

Which of the following substances can sterilize?

Which of the following will NOT destroy prions?