Chapter 11: Physical and Chemical Control of Microbes
The standard temperature-pressure combination for an autoclave is
121 degrees Celsius and 15 psi
_____ is the iodine antiseptic of choice for wound treatment.
5% Iodophor
A sterile object is free of which of the following?
All viable microorganisms and viruses
Which typically describes cold temperatures?
Bacteriostatic
Which molecule is composed of long chains of nucleic acids?
DNA
Which of the following is the mechanical removal of most microbes from animate or inanimate surface?
Decontamination
______ is the general term used for the reduction of the microbial load in order to lower the possibility of infection or spoilage.
Decontamination
What is the process of straining a fluid or air through a membrane to trap microorganisms?
Filtration
Which of the following is the most penetrating?
Gamma rays
Which is the most prominent among antimicrobial physical agents?
Heat
Which level of germicides can function as sterilants?
High
Which of the following is the practical definition of microbial death?
Inability to reproduce
_____ is the process of bombardment with radiation at the cellular level to control microbes.
Irradiation
In what unit is radiation measured?
Kilograys
When microbes are treated with temperatures that exceed their maximum growth temperature, the condition is described as which of the following?
Microbicidal
_____ used for microbial control includes electromagnetic waves with shorter wavelengths.
Radiation
Which of the following describes the main function of the cell membrane?
Selective barrier
Chemical agents that can destroy all forms of life, including endospores, are called with of the following?
Sterilants
What process completely removes or destroys all viable microorganisms, including viruses, from an object or habitat?
Sterilization
Identify the main effect of cold temperatures.
To slow the activity of microbes
_____ radiation is non-ionizing radiation that readily induces mutations.
Ultraviolet (UV)
_____ radiation is the most lethal from 240nm to 280nm.
Ultraviolet (UV)
All of the following describe the typical microbial population targeted by antimicrobial drugs EXCEPT which of the following?
Uniform populations of like microbes
An example of an agent that lowers the surface tension of cells is
alcohol
Antimicrobial solutions with water as the solvent are called _____ solutions, whereas antimicrobial solutions with alcohol or water-alcohol solutions are called _____.
aqueous; tinctures
Microbial control methods are referred to as _____ procedures.
decontamination
A microbicidal agent has what affect?
destroys microorganisms
Any process that destroys the non-spore-forming contaminants on inanimate objects is
disinfection
Radiation is characterized by a range of wavelengths known as the _________.
electromagnetic spectrum
Microbial control methods that kill ____ are able to sterilize.
endospores
Which of the following is an approved sterilant?
ethylene oxide
The most versatile method of sterilizing heat-sensitive liquids is
filtration
The straining of a fluid or air through a membrane to trap microorganisms is known as _____.
filtration
Ionizing radiation like _____ removes ____ from atoms.
gamma rays; electrons
A chemical with sporicidal properties is
glutaraldehyde
Silver sulfadiazine is used
in antisepsis of burns
The bombarding of a substance by waves or particles for diagnosis, therapy, disinfection, or sterilization is referred to as ______.
irradiation
High temperatures _____ and low temperatures ____.
kill cells; inhibit cell growth
The primary mode of action of nonionizing radiation is to
make pyrimidine dimers
The cell _____ is responsible for preventing the loss of important molecules and stopping the entry of damaging substances.
membrane
Regarding the use of the terms microbicidal and microbistatic, higher temperatures are usually _____, whereas lower temperatures are usually _____.
microbicidal; microbistatic
The primary action of ____ heat is to _____.
moist; denature proteins
What type of molecule can be denatured by heat or changes in pH?
protein
The inability to _____ even under optimal growth conditions is the practical definition of microbial death.
reproduce
In dilutions, a small amount of the ____ is diluted in a large volume of solvent to achieve a certain ratio.
solute
In a solution, solutes are dissolved in a liquid known as the _____.
solvent
Detergents are
surfactants
Aldehydes are organic substances that contain a -CHO functional group on a _____ carbon.
terminal
Sanitization is a process by which
the microbial load on an object is reduced
The primary targets of microbial control are microorganisms that cause which of the follow?
~ Food spoilage ~ Disease
Which of the following are examples of physical agents or mechanical means to control microbes?
~ Heat ~ Radiation ~ Filtration
Microbes that are targets of pasteurization include
~ Mycobacterium species ~ Salmonella species