Deck 18: Control of Microbial Growth with Disinfectants and Antiseptics

Question 1

The microbial death rate associated with antimicrobial agents is

A)Sporadic
B)Logarithmic
C)Latent
D)Linear

Answer 1

Logarithmic

Question 2

Which of the following is not used as an antiseptic for skin?

A)Ethanol
B)Iodophor
C)Formaldehyde
D)phenol-containing compounds
E)Hydrogen peroxide

Answer 2

Formaldehyde

Question 3

Which of the following is a mismatched pair?

A)Pasteurization: flash method
B)Non-ionizing radiation: ultraviolet rays
C)Freeze-drying: lyophilization
D)Food preservation: hypotonic medium
E)Pressurized steam: autoclave

Answer 3

Food preservation: hypotonic medium

Question 4

Answer true or false to the reason given in the following statement: The death of a microbe such as a bacterium can be hard to identify,because it is difficult to detect DNA synthesis.

Question 5

Which of the following is a target for disinfectants and antiseptics?

A)Nucleic acid synthesis
B)Cell wall synthesis
C)Plasma membrane
D)Protein structure
E)All of the above

Question 6

Answer true or false to the reason given in the following statement: As the plasma membrane is responsible for enclosing the cytoplasm its loss or damage produces death.

Question 7

Nucleic acids are most sensitive to which of the following procedures

A)Filtration
B)Pasteurization
C)Ionizing radiation
D)Freeze-drying
E)Surfactants

Question 8

Which of the following is a mismatched pair?

A)Silver nitrate: catheters
B)Ozone: water treatment
C)Peracetic acid: food-processing equipment
D)QUATS: mouthwashes
E)Ethylene oxide: bed laundry

Question 9

Which of the following is not a quality of an antimicrobial used for disinfection and antisepsis?

A)It should have a narrow spectrum of activity
B)It should be effective even in the presence of bodily fluids
C)It should not be toxic
D)It should be chemically stable

Question 10

The thermal death time (TDT)is

A)The lowest temperature needed to kill all microbes in 10 minutes
B)The shortest amount of time necessary for complete oxidation
C)The time required for all proteins to denature in a sample
D)The shortest period required to kill all microbes at a particular temperature

Question 11

Which of the following is a mismatched pair?

A)Aseptic: pathogen-free environment
B)Pasteurization: heat to kill pathogens
C)Bacteriocidal: kills all bacteria
D)Sterilization: destruction of all forms of microbes
E)Antisepsis: inanimate objects

Question 12

Which of the following is used to destroy endospores in a liquid medium that will subsequently be used to culture bacteria?

A)Boiling
B)Pressurized steam
C)Filtration
D)Dry heat
E)Pasteurization

Question 13

A bacteriostatic agent is one that

A)Kills the microbe
B)Inhibits the growth of the microbe
C)Creates static electricity when used
D)Is chemically unstable

Question 14

Which of the following is not susceptible to the effects of surfactants?

A)Non-endospore forming Gram-positive bacteria
B)Gram-negative bacteria
C)Non-enveloped viruses
D)Enveloped viruses
E)Protozoans

Question 15

Answer true or false to the reason given in the following statement: Because the phospholipid bilayer of plasma membranes is nonpolar,they have hydrophobic and hydrophilic regions.

Question 16

Degerming is best described as

A)A mechanical process for removing microbes
B)The disinfection of public places
C)The use of heat to kill microbes in food items
D)The use of chemical agents to kill microbes
E)A practice used to maintain a germ-free environment

Question 17

Answer true or false to the reason given in the following statement: Surfactants are very effective for disrupting the plasma membrane of cells because surfactant molecules are oxidants.

Question 18

A solution made by combining alcohol with another antimicrobial compound is a

A)Bisphenolic
B)Tincture
C)Surfactant
D)QUAT

Question 19

Microbial death has occurred if

A)Microbes are no longer able to form endospores
B)Reproductive capability is lost even when microbe is placed in optimal conditions
C)The microbe stops growing
D)DNA mutation rates increase

Question 20

Which of the following statements is true?

A)A chemical agent with a phenol coefficient of 2.0 is less effective than phenol
B)The acronym QUATS stands for quaternary aldehyde compounds
C)The thermal death time for endospores is shorter when moist heat is used than when dry heat is used
D)Eating irradiated food poses risks of developing cancer

Question 21

Answer true or false to the reason given in the following statement: Oxidative reagents are very effective against infections of deep tissues,because they release hydroxyl radicals which kill anaerobic organisms.

Question 22

Answer true or false to the reason given in the following statement: Ionizing radiation useful because it sterilizes without using heat or chemicals.

Question 23

Answer true or false to the reason given in the following statement: The flash method of pasteurization is preferable because it is more effective against Staphylococcus and Streptococcus.

Question 24

Explain what happens when a protein becomes denatured and why this process is likely to be detrimental to microbes.Provide three examples of how proteins can be denatured.

Question 25

Answer true or false to the reason given in the following statement: Hydrogen peroxide is not useful for the treatment of open wounds because the enzyme,lysozyme,which is released from damaged tissues,quickly neutralizes it.

Question 26

Identify and describe five factors that affect the death of microbes by antimicrobial agents.

Question 27

Answer true or false to the reason given in the following statement: The sizes of the zones of inhibition seen with different chemicals are not comparable because bacteria move at different rates.

Question 28

Answer true or false to the reason given in the following statement: The environment in which the microbes to be treated exist is important,because many pathogens will be associated with organic materials such as blood and saliva.