Chapter 11

Question 1

microbial death

Answer 1

Permanent loss of reproductive capability, even under optimum growth conditions

Question 2

Sterilization

Answer 2

The removal or destruction of all viable microbes

Question 3

Sepsis

Answer 3

The growth of microbes in the tissues

Question 4

Asepsis

Answer 4

Techniques that prevent the entry of microbes into sterile tissues

Question 5

Disinfectant

Answer 5

Destruction of vegetative pathogens or inanimate objects

Question 6

Antiseptic

Answer 6

Chemicals applied to body surfaces to destroy or inhibit vegetative pathogens

Question 7

Sanitization

Answer 7

Cleansing techniques that remove microbes and debris from inanimate surfaces

Question 8

Degermination

Answer 8

Cleansing techniques that removes microbes and debris from living tissue.

Question 9

What is the hardest microbe to kill?

Answer 9

prions and endospores (of living bacteria)

Question 10

What is the easiest microbe to kill?

Answer 10

viruses with lipid envelopes

Question 11

moist heat, i.e.

Answer 11

lower temperatures and shorter exposure time; coagulation and denaturation of proteins; i.e. steam

Question 12

dry heat, i.e.

Answer 12

moderate to high temperatures; dehydration, alters protein structure; incineration; i.e. oven

Question 13

What is the most effective at killing microorganisms

Answer 13

moist heat

Question 14

How does heat kill microbes

Answer 14

denatures proteins

Question 15

Thermal death time (TDT)

Answer 15

shortest length of time required to kill all test microbes at a specified temperature

Question 16

Thermal death point (TDP)

Answer 16

lowest temperature required to kill all microbes in a sample in 10 minutes

Question 17

Pasteurization

Answer 17

heat is applied to kill potential agents of infection and spoilage without destroying the food flavor or value; NOT STERILIZATION

Question 18

Tyndallization

Answer 18

Non-pressurized steam; intermittent sterilization for substances that cannot withstand autoclaving

Question 19

Microbiostatic

Answer 19

slows the growth of microbes

Question 20

Lyophilization

Answer 20

freeze drying; preservation

Question 21

Desiccation

Answer 21

Gradual removal of water from cells, leads to metabolic inhibition

Question 22

Osmotic pressure

Answer 22

causes plasmolysis (loss of water from cell due to hypertonic environment) - High salt or sugar concentration is used to help preserve foods

Question 23

Ionizing radiation

Answer 23

deep penetrating power that has sufficient energy to cause electrons to leave their orbit, breaks DNA

Question 24

non-ionizing radiation

Answer 24

little penetrating power so it must be directly exposed

Question 25

examples of ionizing radiation

Answer 25

gamma rays, x-rays, cathode rays

Question 26

examples of non-ionizing radiation

Answer 26

UV light

Question 27

How does non-ionizing radiation (UV light) target inside the cell?

Answer 27

creates pyrimidine dimers which interferes with replication

Question 28

Filtration

Answer 28

Physical removal of microbes by passing a gas or liquid through filter

Question 29

What is filtration used for?

Answer 29

To sterilize heat sensitive liquids and air in hospital isolation units and industrial clean rooms

Question 30

High-level germicide

Answer 30

Chemical decontamination: kill endospores; may be sterilants

Question 31

Intermediate-level germicide

Answer 31

Chemical decontamination: kill fungal spores (not endospores), tubercle bacillus, and viruses

Question 32

Low-level germicide

Answer 32

Chemical decontamination: eliminate only vegetative bacteria, vegetative fungal cells, and some viruses

Question 33

Examples of high-level germicides

Answer 33

Aldehydes (Formeldehyde and glutaraldehyde) Ethylene oxide gas, plasma

Question 34

Examples of intermediate-level germicide

Answer 34

Halogens (Chlorine, Iodine), alcohols (act as surfactants)

Question 35

Examples of low-level germicide

Answer 35

Phenolics, Chlorhexadene, Soaps, silver nitrate, dyes, Quaternary ammonia compounds (quats)

Question 36

Oligodynamic action

Answer 36

Ability of very small amounts of heavy metals to exert antimicrobial activity

Question 37

Nitrosamines

Answer 37

(A carcinogen formed by the combination of nitrite and amino acids) are an increasing concern

Question 38

Which of the following antimicrobials is often required in small amounts and is used to prevent gonorrheal opthalmia neonatorum?

Answer 38

Heavy metals

Question 39

Exposure to heat primarily kills/inhibits microbes by which of the following mechanisms?

Answer 39

Protein denaturation

Question 40

Which of the following is the best method to sterilize heat-sensitive solutions?

Answer 40

Membrane filtration