Chapter 7 Flashcards

Terms Definitions
is the removal or destruction of all forms of microbial life.
A sterilizing agent
control directed at destroying harmful microorganisms
which mostly results in the mechanical removal, rather than the killing, of most of the microbes in a limited area
which is intended to lower microbial counts to safe public health levels and minimize the chances of disease transmission from one user to another
Thermal death point
is the lowest temperature at which all the microorganisms in a particular liquid suspension will be killed in 10 minutes
Thermal death time
the minimal length of time for all bacteria in a particular liquid culture to be killed at a given temperature.
Decimal reduction time
is a third concept related to bacterial heat resistance
is the preferred method of sterilization, unless the material to be sterilized can be damaged by heat or moisture
(heat-resistant) bacteria survive pasteurization, but these are unlikely to cause disease or cause refrigerated milk to spoil
equivalent treatments
as the temperature is increased, much less time is needed ti kill the same number of microbes
One of the simplest methods of dry heat sterilization
in the absence of water, microorganisms cannot grow or reproduce but can remain viable for years. Then, when water is made available to them, they can resume their growth and division.
Ionizing radiation
gamma rays, X rays, or high-energy electron beams --has a wavelength shorter than that of nonionizing radiation, less than about 1nm.
nonionizing radiation
has a wavelength longer that that of ionizing radiation, usually greater than about 1nm. Ultraviolet is the best example.
do not have much direct effect on microorganisms, and bacteria can readily be isolated from the interior of recently operated microwave ovens.
Insert term
Insert definition
/ 17

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})


{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online