Chapter 11 Physical and Chemical Control of Microbes
What are the main effects of ionizing radiation on cellular targets?
-Damage to proteins -Chemical changes in organelles
Disdvantages of UV radiation include____
-Low penetration power -Damage to human tissues
The root-____ is used to indicate killing.
-cide
What suffix (Suffices) indicates the ability to prevent the growth of microorganisms? -cide -static -stasis
-static -stasis
Match each medical device with its classification: 1. Critical 2. Semicritical 3. Noncritical A. Syringe needle B. Blood pressure cuff C. Dental mirror
1. A 2. C 3. B
Which three factors can influence the action of antimicrobial agents?
1. Presence of interfering matter 2. Microbial load 3. Temperature of environment
What factors must be considered in order to adequately sterilize using heat?
1. Presence of water- Moist heat can sterilize objects in less time and lower temperatures than dry heat. 2. Temperature 3. Length of exposure
Which levels of protein structure are disrupted in denaturation? 1. Tertiary 2. Secondary 3. Primary
1. Tertiary 2. Secondary
Select which of the following are examples of dry heat methods of control: 1. Bleach 2. Hot air 3. Incineration 4. Lyophilization 5. Steam
2. Hot air 3. Incineration
Filtration has been used in which of the following? 1. Disposal of biohazards 2. Water purification 3. Decontamination of air 4. Sterilization of medical products 5. Decontamination of milk products 6. Sterilization of powders
2. Water purification 3. Decontamination of air 4. Sterilization of medical products 5. Decontamination of milk products
Treatment of materials to be sterilized with ethylene oxide in a chemiclave requires about____
3 hours
Select the statement that most accurately reflects the use of heat as an antimicrobial agent. 1. Moist heat methods require higher temperatures than dry heat methods. 2. Moist heat methods exert their effects by denaturing lipids. 3. Dry heat methods exert their effect by dehydrating cells. 4. At very high temperatures, moist heat methods oxidize cells to ash.
3. Dry heat methods exert their effect by dehydrating cells.
Which of the following is the most common physical agent used to control microbes? 1. Germicide 2. Cold 3. Radiation 4. Filtration 5. Heat 6. Desiccation
5. Heat
Formaldehyde typically kills microbes by: A) Altering proteins B) Disrupting the cell membrane C) Inhibiting RNA synthesis D) Attaching to nucleic acids
A) Altering proteins D) Attaching to nucleic acids
Chlorhexidine solutions are commonly used for: A) Antisepsis of skin B) Disinfection of medical equipment C) Disinfection of drinking water D) Disinfection of food preparation equipment E) Skin wound care F) Household cleaning
A) Antisepsis of skin E) Skin wound care
Heavy metal germicides come in which of the following forms: A) Aqueous solutions B) Tinctures C) Solid capsules D) Ointments
A) Aqueous solutions B) Tinctures D) Ointments
Which of the following are effects of ionizing radiation on food products? A) Changes in texture of some foods B) Killing of bacterial pathogens C) Large decreases in nutritional value D) Radioactivity of some foods E) Small decreases in thiamine
A) Changes in texture of some foods B) Killing of bacterial pathogens E) Small decreases in thiamine
How are phenolics used in microbial control? Select all that apply: A) Clinical disinfection B) Added to products C) Routine skin antisepsis D) Household disinfection
A) Clinical disinfection B) Added to products D) Household disinfection
A critical concern for the food packaging industry is the elimination of A) Clostridium botulinum B) Bacillus anthracis C) The AIDS virus D) Escherichia coli
A) Clostridium botulinum
Which four of the following are examples of physical agents or mechanical means used to control microbes? A) Cold B) Radiation C) Filtration D) Phenolics E) Germicides F) Heat
A) Cold B) Radiation C) Filtration F) Heat
Chlorhexidine typically kills microbes by: A) Denaturing proteins B) Inhibiting RNA synthesis C) Disrupting the cell wall D) Causing mutation in the DNA E) Disrupting the cell membrane F) Inhibiting protein synthesis
A) Denaturing proteins C) Disrupting the cell wall E) Disrupting the cell membrane
Ethylene oxide typically kills microbes by: A) Disrupting enzyme function B) Causing mutations in the DNA C) Inhibiting RNA Synthesis D) Blocking DNA replication E) Disrupting the cell wall F) Producing toxic radicals
A) Disrupting enzyme function D) Blocking DNA replication
Lower concentrations of alcohols (50% and higher) usually affect microbes by: A) Disrupting the cell membrane B) Inhibiting RNA synthesis C) inhibiting protein synthesis D) Disrupting the cell wall E) Causing mutations in DNA F) Denaturing proteins
A) Disrupting the cell membrane F) Denaturing proteins
Which of the following are types of ionizing radiation? A) Gamma rays B) X-rays C) Ultraviolet rays
A) Gamma rays B) X-rays
What three materials can be effectively autoclaved without destroying their function? A) Glassware B) Rubber C) Heat-sensitive plastic D) Oils and waxes E) Powders F) Cloth
A) Glassware B) Rubber F) Cloth
What are the effects of adding pressure to water in an autoclave? Select all that apply: A) Increases boiling point of water B) Directly kills microbes C) Increases temperature of steam D) Decreases boiling point of water
A) Increases boiling point of water C) Increases temperature of steam
Select which of the following are drawbacks to the use of metals in antimicrobial control methods: A) Microbes develop resistance to these metals B) They are still very active in the presence of biological fluids and wastes. C) They are not associated with allergic reactions D) They can be very toxic to human cells as well as microbial cells.
A) Microbes develop resistance to these metals D) They can be very toxic to human cells as well as microbial cells.
Which of the following are disadvantages of OPA as a disinfectant?: A) OPA does not reliably destroy endospores B) OPA is ineffective against viruses and fungi. C) it tends to stain proteins, including those in human skin. D) OPA can be irritating to eyes and nasal passages.
A) OPA does not reliably destroy endospores C) it tends to stain proteins, including those in human skin.
Which of the following statements are correct regarding OPA? A) OPA is non-irritating to eyes and nasal passages. B) OPA is not effective against viruses. C) OPA is an Aldehyde. D) OPA can reliably destroy endospores.
A) OPA is non-irritating to eyes and nasal passages. C) OPA is an Aldehyde.
Hydrogen peroxide is commonly used for: A) Sterilization of diagnostic instruments B) Disinfection of medical equipment C) Disinfection of drinking water D) Skin and wound cleansing E) Disinfection of food preparation equipment
A) Sterilization of diagnostic instruments B) Disinfection of medical equipmen D) Skin and wound cleansing
Disinfection destroys: A) only vegetative bacterial cells B) only endospores C) only viruses D) vegetative bacterial cells and endospores
A) only vegetative bacterial cells
Which three of the following are common uses for glutaraldehyde? A) preserve vaccines B) retard the growth of molds in bread C) sterilize respiratory therapy equipment D) eliminate hepatitis B viruses on dental equipment E) disinfect skin prior to injecting vaccines F) prevent infection in burn patients
A) preserve vaccines C) sterilize respiratory therapy equipment D) eliminate hepatitis B viruses on dental equipment
____ are organic substances that contain a -CHO functional group on a terminal carbon.
Aldehydes
____ are chemical agents applied directly to body surfaces to inhibit vegetative pathogens
Antiseptics
Antimicrobial solutions with water as the solvent are called ____ solutions, where as antimicrobial solutions with alcohol or water-alcohol mixtures as the solvent are called____
Aqueous, tinctures
____ is a term referring to a condition free of pathogenic microorganisms or a procedure or process designed to prevent the entry of infectious agents.
Asepsis
Which three of the following are examples of disinfection? A) Cleansing a wound with a bleach solution B) A 5% solution of bleach to clean a lab table C) Immersing thermometers in an iodine solution D) Scrubbing hands thoroughly before medical procedures E) Boiling eating utensils
B) A 5% solution of bleach to clean a lab table C) Immersing thermometers in an iodine solution E) Boiling eating utensils
Which two statements regarding cell death rates are correct? A) Bacterial death occurs in a linear manner B) A population of microbes will die at different rates when an antimicrobial agent is applied C) A population of microbes will die simultaneously when an antimicrobial agent is applied D) Bacterial death occurs in a logarithmic manner
B) A population of microbes will die at different rates when an antimicrobial agent is applied D) Bacterial death occurs in a logarithmic manner
Dyes are important for: A) Genotypic testing B) Chemotherapeutic drugs C) Identifying contaminated surfaces D) Staining techniques E) Selective and differential media
B) Chemotherapeutic drugs D) Staining techniques E) Selective and differential media
Glutaraldehyde typically kills microbes by: A) Producing toxic radicals B) Disrupting enzyme function C) Altering amino acids D) Inhibiting RNA synthesis
B) Disrupting enzyme function C) Altering amino acids
Phenolics typically kill microbes by: A) Causing mutations in DNA B) Disrupting the cell wall C) Disrupting the cell membrane D) Denaturing metabolic enzymes E) Inhibiting protein synthesis F) Inhibiting RNA synthesis
B) Disrupting the cell wall C) Disrupting the cell membrane D) Denaturing metabolic enzymes
Which of the following microbial forms are relatively resistant to heat? A) Fungi B) Endospores C) Vegetative cells D) Viruses
B) Endospores D) Viruses
Which of the following is the practical definition of microbial death? A) Altered virulence of cells B) Inability to reproduce C) Altered appearance of cells D) Loss of motility
B) Inability to reproduce
Which are examples of using dry heat to sterilize materials? A) Pasteurization B) Incineration C) Autoclaving D) Hot air oven E) Tyndallization
B) Incineration D) Hot air oven
The effect of a germicide is affected by which of the following factors?: A) Toxicity to human and animal tissues B) Nature of microbial population C) Material being treated D) Contamination with organic matter E) Time of exposure to germicide F) Chemical action of germicide G) Concentration of germicide H) pH of environment
B) Nature of microbial population C) Material being treated D) Contamination with organic matter E) Time of exposure to germicide F) Chemical action of germicide G) Concentration of germicide
Endoscopy equipment becomes highly contaminated with human tissues and fluids, and should be sterilized in a low-temperature cabinet using which sterilants? A) Iodine B) Peracetic acid C) Chlorine Bleach D) Ethanol E) Hydrogen peroxide
B) Peracetic acid E) Hydrogen peroxide
Which of the following compounds are commonly used as gaseous sterilants or disinfectants?: A) Carbonic acid B) Propylene oxide C) Chlorine dioxide D) Ethylene oxide E) Carbon monoxide
B) Propylene oxide C) Chlorine dioxide D) Ethylene oxide
Boiling water can be an effective means of ____ in the clinic and home. Select all that apply: A) Antisepsis B) Sanitization C) Disinfection D) Degermation E) Sterilization
B) Sanitization C) Disinfection
Although they do have some drawbacks, heavy metals are used for: A) Disinfection of medical equipment and facilities B) Skin cleansing C) Disinfection of drinking water D) Disinfection of reusable dental equipment E) Controlling microbial growth on objects F) Prevention of infection G) Preservatives
B) Skin cleansing E) Controlling microbial growth on objects F) Prevention of infection G) Preservatives
Which of the following type of materials can be more reliably disinfected with a germicide? A) Porous objects B) Smooth objects
B) Smooth objects
Which of the following statements about soaps are correct? A) Soaps can destroy most common hospital pathogens. B) Soaps help to mechanically remove surface debris. C) Soaps have a great germicidal value when mixed with heavy metals. D) Soaps are only weakly microbicidal. E) Some bacteria can grow on soap as a nutrient source.
B) Soaps help to mechanically remove surface debris. D) Soaps are only weakly microbicidal. E) Some bacteria can grow on soap as a nutrient source.
Which of the following are not usually destroyed or inactivated with regular pasteurization methods? A) Vegetative bacteria B) Thermophilic microbes C) Endospores D) Vegetative fungi E) Viruses
B) Thermophilic microbes C) Endospores
Which of the following is/are types of nonionizing radiation? A) Cathode rays B) Ultraviolet rays C) Gamma rays D) x-rays
B) Ultraviolet rays
In regards to microbial control of devices that come in contact with patients, which two of the following would be considered a critical medical devices? Select all that apply: A) endoscopy tube B) artificial heart valve C) syringe needle D) crutches E) blood pressure cuff
B) artificial heart valve C) syringe needle
As the most extensively used chlorine compounds, hypochlorites are used for A) sewage and waste water disinfection B) food equipment sanitation C) wound treatment and skin cleansing D) household cleaning E) swimming pool treatments
B) food equipment sanitation C) wound treatment and skin cleansing D) household cleaning E) swimming pool treatments
The property of having antimicrobial effects in exceedingly small amounts is called a(n) ____ action. A) antiseptic B) oligodynamic C) radiative D) degerming
B) oligodynamic
Any process or agent that inhibits bacterial growth is referred to as ____
Bacteriostasis
____ spectrum action is a desirable characteristic of a germicide.
Broad
Heavy metals are reliably: A) Sporicidal B) Microbistatic C) Microbicidal
C) Microbicidal
Sterilization is: A) Always necessary when spores are involved B) Possible for inanimate and animate objects C) Only necessary for certain groups of microbes D) Generally reserved for inanimate objects
C) Only necessary for certain groups of microbes D) Generally reserved for inanimate objects
Which are goals of pasteurization? A) Destruction of endospores B) Sterilization of liquid C) Reduction of microbial load D) Retention of liquid qualities
C) Reduction of microbial load D) Retention of liquid qualities
Metallic ions have which effect on proteins? A) hydrolyze to amino acids B) denature C) bind to the active site
C) bind to the active site
The two broad categories that describe methods for controlling microbes are____ and ____.
Chemical and physical
A common dry heat sterilization method used in the microbiology laboratory is: A) Heating agar in boiling water B) Tyndallization of cultures C) Autoclaving used culture tubes D) Flaming the inoculating loop
D) Flaming the inoculating loop
Hydrogen peroxide typically kills microbes by: A) Disrupting the cell membrane B) Causing mutations in DNA C) Inhibiting protein synthesis D) Producing toxic free radicals E) Inhibiting RNA synthesis F) Disrupting the cell wall
D) Producing toxic free radicals
_____ is the physical removal of surface oils, debris, and soil from skin to reduce the microbial load.
Degermation
Cationic detergents typically work by:
Disrupting the cell membrane
____ heat requires longer exposure times and higher temperatures than ____ heat.
Dry, moist
Which of the following heavy metals are still used in germicidal preparations? A) zinc B) gold C) copper D) arsenic E) silver F) mercury
E) silver F) mercury
Viruses, prions and ____ are relatively resistant to heat.
Endospores
____ oxide is valuable for sterilization of heat-sensitive objects such as plastics, surgical and diagnostic appliances, and spices, but other related gases are available that are less toxic.
Ethylene
Heavy metals typically kill microbes by: A) Causing mutations in DNA B) Producing toxic radicals C) Disrupting the cell wall D) Inhibiting RNA synthesis E) Disrupting the cell membrane F) Inactivating proteins
F) Inactivating proteins
True or False: A process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat is referred to as disinfection.
False
True or False: Biological matter such as serum, blood, or urine increases the effectiveness of a germicide.
False
True or false: A bactericidal agent will inhibit the growth of bacteria, whereas a bacteristatic agent will kill bacteria
False
True or false: Acids or alkalis are limited in their application because they have limited reliability.
False
True or false: Household cleaners are often alcohol based.
False
True or false: Iodine compounds are commonly used for household cleaning.
False
True or false: Ionizing radiation is not an effective method of controlling microbes in food products.
False
True or false: Sepsis is a term referring to a condition free of pathogenic microorganisms or a procedure of process designed to prevent entry of infectious agents.
False
True or false: The characteristics of a microbial population targeted for control do not include microbes with variable resistance.
False
True or false: The phenol coefficient quantitatively compares the effectiveness of a chemical to that of alcohol.
False
True or false: There are several degrees of sterility, based on the destruction of endospores.
False
True or false: 100% alcohol solutions have greater microbicidal activity than 70% solutions
False, because water is necessary to their action on proteins, a lower concentration of alcohol is more effective
True or false: Desiccation is a method for preserving microorganisms (and other substances by freezing and then drying them directly from the frozen state.
False, that's called Lyophilization
True or false: Thymine, uracil, and cytosine are claled purines which are a type of nitogenous bases found in either DNA or RNA
False, they are pyrimidine bases
Formalin is an aqueous solution of ____ gas that is used as a potent chemical fixative and microbicide
Formaldehyde
What types of items are often sterilized using a dry oven?
Glassware and instruments
_____ is one of the few chemicals that is officially accepted as a sterilant and high-level disinfectant
Glutaraldehyde
The dosage of radiation is measured in ____
Grays
The property of having antimicrobial effects in exceedingly small amounts belongs to which class of chemicals?
Heavy metals
____ is the destruction of microbes by subjecting them to extremes of dry heat, reducing them to ashes and gas.
Incineration
____ are complexes of iodine and alcohol.
Iodophors
What type of radiation consists of short-wave electromagnetic rays (such as x-rays) that cause ejection of electrons from target molecules and the creation of ions?
Ionizing radiation
Ethyl and ____ alcohols are effective in microbial control.
Isopropyl
____ is a method for preserving microorganisms (and other substances) by freezing then drying them directly from the frozen state.
Lyophilization
The cell ____ is responsible for preventing the loss of important molecules and stopping the entry of damaging substances.
Membrane
Any process or agent that inhibits bacterial growth is referred to as _____.
Microbiostatic
____ radiation is a method of microbial control that causes the formation of abnormal bonds within the DNA of microbes, increasing the rate of mutation.
Nonionizing
What are the main effects of antimicrobial agents on DNA?
Prevention of replication Permanent mutations
Alcohols are effective against?
Resistant bacteria Enveloped viruses
Which cellular structure is involved in translation?
Ribosome
____ is a decontamination technique that mechanically removes microorganisms and debris from inanimate objects such as utensils to reduce contamination to safe levels
Sanitization
_____ is defined as growth of microorganisms in the blood or other tissues
Sepsis
____ is an alkaline compound made by combining the fatty acids in oils with sodium or potassium salts
Soap
____ is an alkaline compound made by combining the fatty acids in oils with sodium or potassium salts.
Soap
What type of agent specifically destroys endospores?
Sporicide
____ is the destruction of all microbial life, whereas ____ destroys most microbial life, thus reducing contamination on inanimate surfaces.
Sterilization, disinfection
Why do younger, active cells die more quickly when exposed to microbicidal agents?
They are more metabolically active.
The use of waters containing this phenolic for irrigation may lead to the evolution of microorganisms that are resistant to it and other antimicrobials that end up in our food supply.
Triclosan- researchers have identified triclosan resistant microbes across the world
True or False: The primary targets of microbial control are microorganisms that cause infection or spoilage.
True
True or false: A surfactant is an agent that disrupts the lipid bilayer of membranes and alters the membranes permeability
True
True or false: An autoclave is a sterilization chamber that allows the use of steam under pressure to sterilize materials
True
True or false: Cationic detergents are more effective than anionic detergents.
True
True or false: Chlorhexidine is a bactericidal.
True
True or false: Chlorine dioxide disrupts protein function to kill microbes
True
True or false: Death involves the permanent termination of a particular organism's vital processes.
True
True or false: Desiccation is the dehydration of microorganisms in order to inhibit or preserve them.
True
True or false: Drinking water and utensils are reliably sanitized or disinfected by boiled water.
True
True or false: Halogens and alcohols are examples of chemical agents used to control microbes.
True
True or false: Heavy metals inactivate proteins of microbes
True
True or false: Hypochlorites are probably the most extensively used of all chorine compounds; however, chloramines are being employed more frequently as alternatives in treating water supplies due to concern regarding the formation of cancer-causing substances.
True
True or false: If the cell membrane is damaged by an agent, the cell loses its membrane permeability and cannot prevent loss or entrance of substances
True
True or false: Iodine compounds can be sporicidal if used properly.
True
True or false: Quats are rated for only low-level disinfection in the clinical setting.
True
True or false: Radiation is energy emitted from atomic activities and dispersed at high velocity through matter of space.
True
True or false: Soaps and detergents are typical examples of sanitizers.
True
True or false: The halogens are a group of nonmetallic elements with antimicrobial applications, including bromine, iodine, chlorine, and fluorine.
True
True or false: The lowest temperature that achieves sterilization in a given quantity of broth culture upon a 10-minute exposure is referred to as the thermal death point.
True
True or false: The necessity of sterilization or disinfection should be considered when initially choosing a method of microbial control.
True
True or false: The straining of fluid or air through a membrane to trap microorganisms is known as filtration.
True
True or false: The two primary iodine preparations are free iodine and iodophors.
True
True or false: UV radiation is usually used for disinfection.
True
True or false: Death of microorganisms is hard to detect
True, they have no obvious vital signs
_____radiation is a time of nonionizing radiation and is routinely used to disinfect air and the surfaces of solid objects.
Ultraviolet
Degermation and _____ can be accomplished with the same procedures as they pertain to reducing the number of microbes on human skin
antisepsis
Which microbial agent is the most resistant to physical and chemical control methods?
bacterial endospores
gaseous and liquid ____ compounds are mostly used for large-scale water disinfection
chlorine
The shortest length of time required to kill all test microbes at a specific temperature is referred to as the thermal ____ ____
death time
Absolute alcohol (100% concentration) inhibits microbial growth by_____
dehydrating cells
The disruption of proteins from their native state is known as ____
denaturation
Dyes are important for staining techniques, and as selective and ____ agents in media
differential
The goal of regular pasteurization methods is the ____ of the liquid.
disinfection
Flaming the inoculating loop in the laboratory is an example of ____ heat sterilization
dry
Chlorine compounds usually kill microbes by denaturing ____
enzymes
The gas ____ ____ is used to sterilize prepackaged medical devises, syringes, and Petri dishes
ethylene oxide
The effect of germicide is affected by the time of ____
exposure
True or false: Acids and alkalis are commonly used for drinking water disinfection
false
True or false: Cold treatment and desiccation are reliably used for sterilization or disinfection.
false
True or false: Heavy metals are microbistatic
false
True or false: Phenolics are microbiostatic.
false
True or false: Sterilization methods are often used to prepare the human body for surgical procedures
false
True or false: Using ethylene gas in a room is an example of sanitation
false
True or false: ionizing radiation is not an effective method of controlling microbes in food products
false
True or false: Halogens are only microbiostatic.
fasle
The ____ method of pasteurization exposes liquids to higher temperatures for a very short time, whereas the ____ method uses lower temperatures for a longer period.
flash, batch
The two aldehydes used most often in microbial control are ____ and ____
glutaraldehyde, formaldehyde
Prions are very resistant to chemicals and inactivation by ___ including autoclaving
heat
____ sensitive plastic may not be autoclaved
heat
Ionizing radiation is a good technique for sterilizing materials that are sensitive to ____ or ____.
heat, chemicals
Glutaraldehyde is one of the few chemicals that is officially accepted as a sterilant and _____-level disinfectant
high
The dry oven is not suitable for items that may burn at ____ temperatures, or for liquids which will ____
high, evaporate
Disinfectants are normally used only on inanimate objects because they can be toxic or harmful to ______ and other_____tissues.
human, animal
Plasmolysis of bacteria in foods occurs when high concentrations of salt or sugar are added to the foods creating a _____ environment
hypertonic
The use of sugar or salt to preserve food creates a ____ environment for the bacteria in the foods.
hypertonic
A virucide ____ viruses
inactivates.
Fungicides ____ fungal spores, hyphae, and yeasts
kill
bactericides ____ bacteria
kill
Quaternanry ammonium compounds are considered to be ____ -level disinfectants.
low
If an agent disrupts the cell wall, the cell is likely to experience death by ____
lysis
Although heavy____ exert potent antimicrobial effects, their risk to human health through toxicity, allergic reactions, and resistance has limited their use in medicine.
metals
An agent's effect on cells is known as its ____ of action.
mode
Agents that are highly selective in their targets are usually effective against a ____ range of microbes.
narrow
The normal 3-dimensional state of a protein is called its ____ state
native
The heat treatment of perishable liquids to destroy heat-sensitive vegetative cells and prevent infection and spoilage is called ____
pasteurization
One approach to controlling bacteria and fungi is by ____ the synthesis of the cell wall
preventing
The two types of macromolecules that make up the majority of the cell membrane in organisms are ____ and ____.
protein, lipid
Iodine compounds typically kill microbes by denaturing ____.
proteins
Nucleic acids are involved in the process of translation to synthesize _____, chains of DNA-encoded amino acids.
proteins
The four general cellular targets of antimicrobial agents are the cell wall, the cell membrane, nucleic acid synthesis and____
proteins
A ____ _____ is the union of 2 adjacent pyrimidines on the same DNA strand, brought about by exposure to ultraviolet light
pyrimidine dimer
Pure forms of this metal are currently incorporated into catheters to prevent urinary bladder infections in the hospital
silver
The main effect of cold treatment is to____
slow the activity of microbes
Household bleach is known by its chemical name____
sodium hypochlorite
A ____ agent can also be a sterilant because it can destroy bacterial endospores and leave an object free of all life.
sporicidal
An object is ____ if it is free of all viable microorganisms including viruses
sterile
Medical devices that become heavily contaminated with human tissues and fluids, must be carefully _____ using low-temperature cabinets that employ oxidizing agents such as hydrogen peroxide and paracetic acid
sterilized
The ____ and ____ levels of protein structure are disrupted in denaturation.
tertiary, secondary
In general, planktonic bacteria are more susceptible to control agents than biofilm bacteria because
the extracellular biofilm matrix provides protection from control agents
Antimicrobial solutions with alcohol or water-alcohol mixtures as the solvent are called_____
tinctures
One of the most widely used phenolics used today is ____
triclosan
Scientist have demonstrated ____ resistance found in organisms, such as E. coli, leads to antibiotic resistance by these organisms.
triclosan
True or false: Soaps and quats are commonly used for sanitation of the home
true
True or false: Acids or alkalis are limited in their application by their corrosive and hazardous nature.
true
True or false: Surgical handwashing is an example of degermation
true
True or false: Ultraviolet radiation is most lethal from 240nm to 280nm
true
True or false: Weak tinctures of heavy metals may be used as antiseptics on intact skin.
true
Desiccation can preserve foods by reducing the availability of ____ to microbes for their metabolism
water