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Flashcards in Chapter 5 Deck (39):

A) What is the process of sterilization?

heat, filtration, chemicals, irradiation ????


1) What does it mean for something to be sterile?

all the bacteria are all removed/ killed in a certain product... free of microbes.(doesn't include prions)


B) What is the process of disinfection?

eliminaiton of most or all pathogens are removed from a product.


1) What can disinfectants do?

remove/ kill microorganisms


2) What are germicides? What does it mean to be bactericidal?

Are a disinfectant that kill bacteria. that is what bactericidal means... they kill bacteria


3) What are antiseptics?

antimicrobial chemicals that are not too toxic and can be used on the skin.


C) What is pasteurization?

when you heat a liquid high temp a short time (typically). used to destroy heat sensitive organisms


D) What is the process of decontamination?

process to reduce micro o. to a level that is considered safe to handle.


E) What is the process of sanitization?

substantial reduction of a pop. to meet accepted health standards


F) What is the process of preservation?

delaying spoilage of food, by chemicals, storage of food etc.


1) What does it mean to be bacteriostatic?

inhibit growth of bacteria, but do not kill them


G) Which situations warrant microbial control? [Figure 5.1]

in homes, hospitals, food and water plants


H) What are healthcare associated infections?

infections linked to hospitals/ clinics


I) What is the aseptic technique? How does it relate to BSL levels?

methods used to keep from contaminating samples you are working with. Bio safety levels wich rate how dangerous a pathogen is. and helps you know procedures to keep you safe.


K) What are disinfection by-products and what are the health risks?

when chemical reacts with naturally occuring chemicals in water and have been linked to long term health risks


A) Which are the highly resistant microbes?

Bacterial endospores, protazoan cyst/ oocytes, mycobacterium, pseudomonas species, naked virus


B) What is the D value and what is it used for? [Figure 5.2]

decimal reduction time: time required to kill 90% of a microbial pop. under specific conditions


C) What environmental conditions can affect death rates in microbe populations?

temp. and ph


D) Which instruments pose greater threat of transmission of microbes?

used in invasive proceedures aka needles ect.


E) How does the type of material dictate the sterilization and disinfection procedures?

some can handle heat, others are chem sensitive.


A) What physical methods are used to destroy microorganisms and viruses? [Table 5.1]

heat, dry heat, filtration, radiation, high pressure


1) What does high-temperature-short-time and ultra-high-temperature processing mean?

these are refering to pastuerization


2) What are autoclaves? What are they used for? [Figure 5.3 and 5.4]

heat and pressure to create steam to sterilze


3) What does it mean to be commercially sterile?

endospores and thermophils may have survived


A) What are membrane filters and what do they do? [Figure 5.5]

microscopic pores that let water through, but not the microo. (typically .2 micrometers.


B) What are depth filters?

trap material withing thick porous filtration material.


C) What are HEPA filters?

air filter remove .3 micrometers or bigger


D) What is electromagnetic radiation? [Figure 5.6]

short waves high E. x rays, gammarays, uv rays ect.


1) What is ionizing radiation and how is it used against microbes?

destroys dna and cytoplasmic membranes


2) What is ultraviolet radiation and how is it used against microbes?

uv light 220 to 300nm damages dna, so affects more so replicating org.


3) What are microwaves and can they be used against microbes?

the waves themselves don't do anything, but the heat can.


E) How can high pressure be used against microbes?

high pressure used so you don't use heat.the pressure is believed to denature protiens (13000psi)


A) How are germicides grouped according to their potency? (What are the groups?)

Sterilants: kills all micro o's inclueding endospores "sporillants" Takes 6-10 hours to kill endospores
High level disinfectants: destroys viruses and vegatative micro o's
Intermediate level: destroy all vegitateive bacteria and mycobacteria, fungi, and most viruses
Low level: fungi and vegit. bacteria ( not mycobacteria)


B) What points should be considered when choosing a germicide?

Toxicity, reaction with org molec., compatability with ,material, residue, cost and availability storage stability, environmental risk


C) What are the characteristics and uses of the germicidal chemical groups? [Table 5.2

Alchohols: aqeuos solutions as antiseptics and disinfect instraments
Aldehydes: sterilize med equip. used in some vaccines and preserve bio. specimens
Biguanides:antiseptic in soaps and lotions. Impregnated in catheters and mesh
Ethylene oxide gas: sterilize med equip.
Metals:used in topical dresssings, prevent eye infection in new borns
Ozone: disinfect water
Peroxygens:sterilize containers ie milk jugs etc and med supplies
Phenolic compounds:in toothpaste lotions and deodorant, but only in limited amouns cause it can cause neurological damage
Quanternary ammonium compounds: preserve non food substnces and disinfect


A) What are some of the chemical preservatives that can be used on food items?

Benzoic, sorbic and prepionic acid , nitrate in meats


B) How do low temperatures, salting and drying preserve food?

Low temp: inhibits growth of pathogens
Water and salt: inhibit growth due to lack of water and high salt concentratioin leads o plasmolysis


1) Why is sugar or salt used when canning? [Figure 5.8]

Lead to dehydrating cells


2) What is lyophilization?

Freeze drying!