chp 11 micro sb

Which of the following are examples of disinfection? Wiping skin with alcohol before an immunization Cleansing a wound with a peroxide solution A 5% solution of bleach to clean a lab table Boiling eating utensils Immersing thermometers in an iodine solution

A 5% solution of bleach to clean a lab table Boiling eating utensils Immersing thermometers in an iodine solution

One of the greatest concerns in the canning industry is to prevent the growth of which of the following bacteria? Helicobacter pylori Streptococcus pyogenes Clostridium botulinum Borrelia burgdorferi

Clostridium botulinum

The microbial agents that are least resistant to physical and chemical control methods include which of the following? Bacterial vegetative cells Enveloped viruses Bacterial endospores Protozoan cysts

Bacterial vegetative cells Enveloped viruses

Which term describes the removal of water that can lead to the death of some microbes? Desiccation Hydrolysis Condensation

Desiccation

Which of the following are effects of ionizing radiation on food products? Changes in texture of some foods Killing of bacterial pathogens Radioactivity of some foods Large decreases in nutritional value Small decreases in thiamine

Changes in texture of some foods Killing of bacterial pathogens Small decreases in thiamine

True or false: Most vegetative forms of microorganisms are susceptible to the same exposure to heat.

False, Vegetative cells vary in their sensitivity to heat.

True or false: Incineration is an example of using moist heat to sterilize or disinfect materials.

False: Incineration is an example of dry heat.

True or false: Chilling, freezing, and dessication are reliably used for sterilization or disinfection.

False: One cannot be sure pathogens have been killed since these methods are uncertain.

True or false: At cold temperatures, all microorganisms are inhibited and can no longer secrete their toxins.

False: Some psychrotrophs will continue to grow and secrete their toxic products

What is the process of straining a fluid or air through a membrane to trap microorganisms? Filtration Radiation Pasteurization

Filtration

_______ radiation is non-ionizing radiation that readily induces mutations.

UV

________ radiation is most lethal from 240nm to 280nm.

UV

Which microbial agent is the most resistant to physical and chemical control methods? Bacterial endospores Mycobacterium cells Protozoan cysts Fungal spores

bacterial endospores

At sea level, water boils at which temperature? 100 C 80 C 1000 C 60 C

100 c

Which of the pressure/temperature combinations is the most efficient for autoclaving? 45 psi and 1000C 50 psi and 2120C 30 psi and 1320C 15 psi and 1210C

15 psi and 1210C

All non-heat resistant forms of bacteria, yeasts, molds, protozoa, worms and viruses are destroyed by exposure to 80οC for which minimum amount of time? 20 seconds 20 minutes 10 minutes 2 days

20 mins

A sterile object is free of which of the following? All viable microorganisms except viruses All viable microorganisms and viruses Almost all viable microorganisms and viruses Everything except endospores

All viable microorganisms and viruses

_______, _______, and _______ are pyrimidine nitrogenous bases that are found in DNA or R

Blank 1: Thymine Blank 2: Cytosine Blank 3: Uracil

Which are examples of using moist heat to sterilize or disinfect materials? Boiling Pasteurization Incineration Hot air oven Autoclaving

Boiling Pasteurization Autoclaving

Identify any chemical agent used to control microbes. Multiple select question. UV light Detergents Heavy metals Halogens

Detergents Heavy metals Halogens

The primary targets of microbial control are microorganisms that cause which of the following? Disease Food spoilage Antibiotic production Microbial antagonism

Disease Food spoilage

Which of the following terms is used to describe an agent that inhibits fungal growth? Fungistasis Fungilimbo Fungistatic Fungicidal

Fungistatic

Which of the following can cause permanent inactivation of microbial DNA? Ethylene oxide Gamma rays Ultraviolet rays Formaldehyde

Gamma rays Ultraviolet rays

Antimicrobial chemicals can exist in what physical states? Low-level High-level Gas Liquid Solid

Gas Liquid Solid

Which of the following viruses is the most resistant to heat? Adenoviruses Hepatitis A

Hepatitis A

Sterile milk is typically generated by which of the following? GMO cows Autoclaving Incineration High heat Filtration

High heat

Which of the following is the practical definition of microbial death? Inability to reproduce Altered virulence of cells Loss of motility Altered appearance of cells

Inability to reproduce

Which of the following is the principal benefit of cold treatment? Inhibition of microbial activity Sterilization of foods/liquids Destruction of microbes Increased death rate of microbes

Inhibition of microbial activity

Which of the following describe sterilization? It is always necessary when spores are involved. It is possible for inanimate and animate objects. It is generally reserved for inanimate objects. It is only necessary for certain groups of microbes.

It is generally reserved for inanimate objects. It is only necessary for certain groups of microbes.

Which is the definition of sepsis? It is death of tissue due to microbial growth. It is growth of microorganisms in the water supply. It is growth of microorganisms in the blood or other tissues.

It is growth of microorganisms in the blood or other tissues.

Which of the following describes sterilization of the skin? It is highly dangerous and impractical. It is hard to do but not dangerous. It is easily done.

It is highly dangerous and impractical.

Identify the beneficial effects of irradiated food. Reduction of bacterial pathogens Food is radioactive Shorter shelf life Longer shelf life

Longer shelf life Reduction of bacterial pathogens

Disadvantages of UV radiation include which of the following? Delayed results Low penetration power High heat requirement Damage to human tissues

Low penetration power Damage to human tissues

Which of the following processes avoids the formation of ice crystals, which can damage cells? Lyophilization Dessication Freezing

Lyophilization

______ is a method for preserving microorganisms (and other substances) by freezing and then drying them directly from the frozen state.

Lyophilization

What materials require intermediate germicides? Invasive medical devices Medical devices that contact the skin Medical devices in contact with membranes

Medical devices in contact with membranes

What materials are disinfected with low-level germicides? Medical devices in contact with membranes Medical devices that contact the skin Invasive medical devices

Medical devices that contact the skin

When microbes are treated with temperatures that exceed their maximum growth temperature, the condition is described as which of the following? Microbicidal Microbistatic

Microbicidal

When microbes are treated with temperatures that exceed their maximum growth temperature, the condition is described as which of the following? Microbistatic Microbicidal

Microbicidal

The effect of a germicide is affected by which of the following factors? Multiple select question. Nature of microbial population Material being treated Chemical action of germicide Toxicity to human and animal tissues Time of exposure to germicide Contamination with organic matter Concentration of germicide

Nature of microbial population Material being treated Chemical action of germicide Time of exposure to germicide Contamination with organic matter Concentration of germicide

Identify the 4 general cellular targets of antimicrobial agents. Nucleic acid synthesis The cell wall Extracellular appendages The cell membranes Protein function DNA contained in plasmids Capsules

Nucleic acid synthesis The cell wall The cell membranes Protein function

Disinfection destroys which of the following? Only viruses Bacterial cells and endospores All types of microorganisms Only vegetative cells

Only vegetative cells

regular ______ does not sterilize milk and other beverages.

Pasteurization

Which of the following are some of the desirable qualities in a germicide? Penetrating ability Solubility in a solvent Broad-spectrum action Narrow-spectrum action Rapid action Inactivated by organic matter

Penetrating ability Solubility in a solvent Broad-spectrum action Rapid action

Sterilization is achieved using an autoclave for which of the following reasons? It is used over a period of hours to ensure proper killing of all microbes. Pressure in the chamber increases the temperature of the steam. The heat inside of the chamber is at a temperature over 10000C.

Pressure in the chamber increases the temperature of the steam.

Antimicrobial agents affect microbial DNA in what ways? Prevent transcription Stop peptide bond formation Cause mutations Inhibit replication Break double helix

Prevent transcription Cause mutations Inhibit replication

Which of the following is a microorganism that can survive at low temperatures? Psychrotroph Mesophile Anaerobe Thermophile

Psychrotroph

Which are goals of pasteurization? Reduction of microbial load Retention of liquid qualities Destruction of endospores Sterilization of liquid

Reduction of microbial load Retention of liquid qualities

Which explains why food items in the refrigerator eventually spoil? Multiple choice question. Food spoils due to molecules falling apart. The refrigerator is microbicidal. Refrigerator temperature only slows the activity of most microbes.

Refrigerator temperature only slows the activity of most microbes.

UV radiation is effective at disinfecting which types of materials? Air Entire solid objects Solid surfaces Liquids

Solid surfaces Liquids air

Which of the following vegetative bacterial cells is more resistant to moist heat? Neisseria gonorrhoeae Staphylococcus aureus

Staphylococcus aureus

Chemical agents that can destroy all forms of life, including endospores, are called which of the following?

Sterilants

Which of the following can be high-level germicides? Antiseptics Sterilants Disinfectants

Sterilants

All of the following describe the typical microbial population targeted by antimicrobial drugs except which of the following? Complex mixtures of microbes Microbes with variable pathogenic capabilities Uniform populations of like microbes Microbes with variable resistance

Uniform populations of like microbes

Which of the following describes dry heat? High humidity Very high temperatures 60-135ο C Low moisture

Very high temperatures Low moisture

In sterilization, which of the following are removed or destroyed? All microorganisms Bacteria and viruses but not endospores Only bacteria

all microorganisms

______ is a term referring to a condition free of pathogenic microorganisms or a procedure or process designed to prevent entry of infectious agents.

asepsis

Which of the following devices would not be used for dry heat conditions? Electric heating coil Oven Autoclave Flame

autoclave

______ water can be an effective means of disinfection in the home.

boiling

______ spectrum action is a desirable characteristic of a germicide.

broad

Decontamination methods employ either _______ or physical agents to destroy microorganisms.

chemical

_____ temperatures and desiccation cannot be reliably used for sterilization or disinfection.

cold

Which of the following factors plays the largest role in antimicrobial activity? Relative humidity Relative pH Concentration Temperature

concentration

When a certain threshold of a microbicidal agent is reached, ______ occurs in the microbial population in a logarithmic manner.

death

_______ involves the disruption of protein structure which results in the loss of function.

denaturation

Moist heat works mostly by which of the following ways? Dehydrating the cell Denaturing proteins Destroying the cell wall Oxidizing the cell to ashes

denaturing the cell

The dehydration of pathogens that can lead to either death or preservation is referred to as ________

desiccation

A pyrimidine _________ is the union of two adjacent pyrimidines on the same DNA strand, brought about by exposure to UV light.

dimer

The straining of a fluid or air through a membrane to trap microorganisms is known as

filtration

With a small enough pore size, _______ can allow for true sterilization by removing bacteria and viruses.

filtration

What must be considered to ensure adequate sterilization by heat? Temperature Concentration Pressure Length of exposure

temperature and length of exposure

What is adjusted when autoclaving large, bulky loads instead of light loads? Multiple choice question. Temperature Duration Concentration Pressure

duration

Radiation is characterized by a range of wavelengths known as the ______ _______

electromagnetic spectrum

Viruses, prions, and ______ are relatively resistant to heat.

endospores

The effect of a germicide is affected by the time of _____

exposure

True or false: All viruses have the same susceptibility to heat. True false question.

false

True or false: Ionizing radiation is not an effective method of controlling microbes in food products

false

True or false: Ionizing radiation is not an effective method of controlling microbes in food products.

false

Which level germicides can function as sterilants? Intermediate Low High

high

Sterilization methods are usually reserved for which of the following? Inanimate objects Food utensils Living tissue

inanimate objects

The bombarding of a substance by waves or particles for diagnosis, therapy, disinfection, or sterilization is referred to as _______

iradiation

Regarding the use of the terms _______ , higher temperatures are usually , whereas _______ lower temperatures are usually .

microbicidal and microbistatic

Many perishable substances are processed with ______ heat to allow for shelf storage time of months or years.

moist

_________ heat works primarily by denaturing proteins.

moist

Agents that are highly selective in their targets are usually effective against a _______ range of microbes.

narrow

Which is the principal macromolecule in cells affected by UV radiation? Carbohydrates Nucleic acids Proteins Lipids

nucleic acids

The heat treatment of perishable liquids to destroy heat-sensitive vegetative cells and prevent infection and spoilage is called_____

pasteurization

Most sterilization is performed using a agent, _______ such as heat

physical

The _______ must be increased to raise the temperature at which water boils.

pressure

Which level of protein structure is typically the most difficult to disrupt? Secondary Primary Tertiary

primary

Which disease agent is most likely to pass through a filter? Bacteria Prions Fungi Viruses

prions

______ used for microbial control includes electromagnetic waves with shorter wavelengths.

radiation

The inability to ______ even under optimal growth conditions is the practical definition of microbial death.

reproduce

Which cellular structure is involved in translation? Cell wall Cell membrane Ribosome Smooth ER Nucleus

ribosome

Which type of material cannot be penetrated by non-ionizing radiation? Liquids Gases Solids

solids

The disadvantages of UV radiation include the inability to penetrate ________ substances and the damaging effect on human __________ .

solids, tissue/skin

The root - _____ is used to indicate the inhibition of microbial growth.

static or stasis

An autoclave is a sterilization chamber that allows the use ________ of under pressure to _______ materials.

steam, sterilize

Which of the following is the biggest disadvantage in the use of boiling water for disinfection? Multiple choice question. The danger to the person involved The quick recontamination of items The inability to kill resistant bacteria The limitations of use in the home

the quick recontamination of items

Typically, increases to temperature can result in a ________ reduction in to ensure adequate sterilization by heat.

time

The synthesis of proteins involves ribosomes that are used in a process called ______

translation

Chemical agents used to control microbes include all of the following except which one? Carbon dioxide Detergents Phenolics UV light Heavy metals Alcohols Aldehydes Halogens

uv light

Which of the following disinfection methods is desirable for air treatment? Misting chemicals Heat/flame UV light

uv light

Desiccation can preserve foods by reducing the availability of which element/compound to microbes necessary for their metabolism? Oxygen Water Glucose Carbon dioxide

water

Radiation of pork products can reduce the number of Trichinella, which are what type of microbe? Protozoan Bacterium Worm Virus

worm