Exam 3 Flashcards
prokaryotes
no nucleus (bacteria)
eucaryotes
have nucleus (protozoa, fungi)
bacteria shapes
spherical (staphylococcus) rod shaped (E. coli) twisted spirillum (campylobacter)
difference between Gram+ and Gram-
Gram+ thick cell wall; Gram- thin wall, easier to inactivate in foods
spore
bacterial response to unfavorable conditions; survival mechanism
molds
multi or unicellular, found in decaying organic matter
molds grow as a tangled mass called
mycelium
mycelium is composed of filaments called
hyphae
yeasts
spherical or oval single shaped cells
how do bacteria reproduce
binary fission
generation time
time between divisions
factors affecting microbial growth
food acidity time temperature oxygen moisture
in what pH conditions do bacteria grow best
slightly acidic (6.6-7.5)
danger temperature zone
40F-140F
aerobes
pathogens that need O2
hurdle concept
sub-lethal levels of growth affecting factors are used to inhibit or reduce microbes in food
food safety
disease producing or toxic hazard accidentally introduced into food supply
food security
intentional contamination of food as a result of criminal action
food borne illness
illness resulting from ingestion of food
trinity of factors for a FBI
pathogen, host, exposure (food)
infection
when infectious bacteria invade GI tract, cause an imbalance in osmotic pressure, and thus illness
intoxication
bacteria produce toxins, which are quickly absorbed through the intestinal tract and cause diseases
intoxification
combination of intoxication and infection, caused by microbes that produce toxins once in the GI tract
3 reasons for FBI outbreaks
improper cooking, improper storage, contamination without treatment before consumption
best known measure to prevent biological hazard of FBI
refrigeration
HACCP
Hazard analysis critical control points
hazard
any biological, chemical, or physical entity that can harm the consumer
significant hazard
high probability of occurrence
critical control point
step during the process for which control is essential to produce the safest food possible
critical limits
numerical values that if exceeded or not met result in loss of control of the particular CCP
microorganisms
living entities too small to be seen with naked eye
