Chapter 9 Flashcards
treatment of an object to ensure destruction of all living microbes, spores, and viruses
sterilization
the process of killing all pathogens in a product, particularly in the food supply
commercial sterilization
reduces the numbers of pathogens or discourages their growth on inanimate objects
disinfection
reduces pathogen numbers to levels considered safe by public health standard
sanitization
agent that kill microbes
microbicidals
agent that specifically target and kill bacteria
bactericidals
agents that specifically target and kill fungi
fingicidals
agent that inhibit growth of all microbes
microbiostatics
agent that inhibit the growth of bacteria
bacteriostatics
agents that inhibit the growth of fungi
fungistatics
microbial growth control agents exert their effect by:
targeting cellular structures and interfering with metabolic activities
the bacterial cell envelope consists of:
cell wall damage and phospholipids/cell membrane proteins
elevated _________ is a common physical control method
temperature
the effectiveness of heat for sterilization is a function of ________ and _________
time and temperature
at temperatures above the growth range, what happens
proteins and nucleic acids are destroyed and water is removed
uses direct flame to kill microbes
incineration
______________ ovens do not penetrate materials easily, but long-term exposure to high temperatures can be used for sterilization
hot air
what degrees Celsius for two hours will sterilize most objects
160 degrees celsius
requires long periods of exposure to high temperatures
dry heat
effective at a lower temperature than dry heat
moist heat
used in an autoclave as a more dependable way to sterilize a variety of objects
pressurized steam
what pressure, temperature, and time are used in pressurized steam
15 psi at 121 degrees Celsius for 15-30 minutes
reduces bacterial populations in food and drink
pasteurization
________ temperatures slow microbial growth
cold
retards metabolic activity of microbes but does not kill them
refrigerators
___________ prefer colder temperatures and can contaminate foods
psychrophiles
as fluid passes through a membrane filter, organisms above a certain size threshold are trapped in the pores
liquid filtration
air can be filtered using a _____________ filter
high-efficiency particulate air
can be used to control microbial growth
ultraviolet light
_______ and _________ force electrons out of microbial molecules; this affects cell metabolism and physiology
x-rays and gamma rays
used to destroy pathogens on living tissue
antiseptics
used on inanimate objects to reduce or eliminate pathogens
disinfectants
mechanically removing organisms from an objects surface
degerming
keeps bacterial populations low in municipal water supplies
chlorine
used as a disinfectant and as an antiseptic on wounds
iodine
interfere with microbial metabolism
heavy metals
_________, ___________, and __________ are reactive proteins
mercury copper and silver
denature proteins and disrupt membranes by lipid dissolution
alcohols
what percent alcohol is used to disinfect surfaces
70
removes microbes by emulsifying and solubilizing particles on the skin
soaps
are surfactants
detergents
damages cellular components
hydrogen peroxide
cause cross-linking that inactivates proteins and nucleic acids
aldehydes
used on heat-sensitive plastics
sterilizing gases
