chapter 9

Question 1

use of heat to kill pathogens that cause spoilage of food products without causing damage to the product itself

Answer 1

pasteurization

Question 2

the removal and destruction of all microbes in or on an object which include viruses and endospores

Answer 2

sterilization

Question 3

procedure that is free of contamination by pathogens

Answer 3

aseptic

Question 4

removal of microbes by mechanical means

Answer 4

degerming

Question 5

agents that inhibit the growth of a microorganism

Answer 5

static

Question 6

agents that kill a microorganism

Answer 6

cidal

Question 7

kills bacteria

Answer 7

bactericide

Question 8

prevents bacteria from reproducing

Answer 8

bacteriostatic

Question 9

an antimicrobial used to kill microorganisms on non living surfaces or inanimate objects, more concentrated

Answer 9

disinfectant

Question 10

an antimicrobial used to kill microorganisms on skin or body tissues

Answer 10

antiseptic

Question 11

remove microbes from a public space to health standards set by the government, level can differ based on location

Answer 11

sanitization

Question 12

a chemical that kills or suppresses growth of microbes

Answer 12

antimicrobial agent

Question 13

four ways antimicrobial agents work

Answer 13

1. alter cell wall
2. alter cell membrane
3. damage proteins
4. damage to nucleic acids

Question 14

how can antimicrobial agent alter cell wall

Answer 14

place in a hypotonic solution, water is higher outside the cell wall, it will cause water to flow into bacteria cell and it will burst

Question 15

function of cell membrane

Answer 15

controls passage of chemicals entering and exiting the cell

Question 16

what happens if we damage cell membrane

Answer 16

vital chemicals will leak out of the cell which results in immediate death within seconds

Question 17

how do proteins function

Answer 17

the act as enzymes in metabolism and structural components of organelles and cells

Question 18

what does protein function depend on

Answer 18

3D shape

Question 19

DNA and mRNA are involved in

Answer 19

gene expression

Question 20

what makes the ideal antimicrobial agent

Answer 20

• inexpensive
• fast acting
• long shelf life for storage
• selectively kills microbes while harmless to humans and environment

Question 21

list microbes from most resistant (hardest to kill) to most susceptible

Answer 21

prions
bacterial endospores
mycobacteria
cysts of protozoa
active-stage protozoa
most gram - bacteria
fungi
nonenveloped viruses
most gram + bacteria
enveloped bacteria

Question 22

have the ability to transfer their folding to other variants of that protein, they cause fatal neurodegenerative diseases that can be transmitted, indestructible

Answer 22

prion

Question 23

surrounded by a lipid membrane but makes them easier to destroy through sterilization

Answer 23

enveloped viruses

Question 24

what virus lacks a lipid membrane

Answer 24

noneveveloped viruses

Question 25

If the temperature is too high what will happen

Answer 25

it will degrade or breakdown the chemical disinfectants or antiseptics

Question 26

how do chemical disinfectants work best

Answer 26

they work poor in cold environments as chemicals move and react slower the work well in warm environments as chemicals move and react faster at high temps

Question 27

a chemical agent that kills pathogenic microorganisms

Answer 27

germicide

Question 28

germicides used on invasive medical equipment needed on implants, catheters, lung machines

Answer 28

high-level

Question 29

germicides that kill fungal spores, viruses, and pathogenic bacteria but not endospores, come in contact with the mucous membrane

Answer 29

intermediate-level

Question 30

germicides that eliminate vegetative bacteria, fungi, protozoa, and some viruses, only equipment that comes in contact with the skin

Answer 30

low-level

Question 31

why is heat an effective method in killing microbial life

Answer 31

it uses all four strategies to kill microbes -denatures proteins -disrupts integrity of the membrane and cell wall -unwinds double strands of DNA

Question 32

lowest temp that kills all cells in broth in 10 min

Answer 32

thermal death point

Question 33

time to sterilize volume of liquid at a set temp

Answer 33

thermal death time

Question 34

is moist or dry heat more effective in killing microorganism

Answer 34

moist heat

Question 35

why is moist heat more effective

Answer 35

heated water has more heat/energy to destroy bacteria when it collides with it, it also absorbs the cell better because it has more water content

Question 36

boiling time depends on what

Answer 36

elevation higher elevation: boils quicker but has less energy so more time to kill microbes

Question 37

pressure applied to boiling water prevents steam from escaping

Answer 37

autoclaving

Question 38

standard autoclave conditions

Answer 38

121C 15psi 15 min

Question 39

used to kill microbes in milk, ice cream, yogurt, wines, beers, and fruit juices

Answer 39

pasteurization

Question 40

used for materials that cannot be sterilized with moist heat because they would breakdown or become damaged in the steam

Answer 40

dry heat

Question 41

how does dry heat kill bacteria

Answer 41

denatures proteins and oxidizes structural biochemicals and enzymes

Question 42

what is the ultimate means of sterilization

Answer 42

complete incineration

Question 43

what is most effective way of freezing

Answer 43

slow freezing

Question 44

what inhibits growth due to removal of water

Answer 44

dessication

Question 45

what is used for long-term preservation of microbial cultures

Answer 45

lyophilization

Question 46

method used to physically remove microorganisms from a liquid

Answer 46

filtration

Question 47

adding high concentrations of sugar or salt to food will inhibit growth of microbe

Answer 47

osmotic pressure

Question 48

the solute concentration is higher outside the cell than inside, water travels from high to low, cell shrinks

Answer 48

hypertonic solution

Question 49

short wavelengths =

Answer 49

greater energy and more penetration

Question 50

wavelengths that are less than 1 nm

Answer 50

ionizing radiation

Question 51

which is non-ionizing radiation

Answer 51

ultraviolet rays

Question 52

largest wavelength are very effective at surface killing but do not penetrate cells so it is the weakest

Answer 52

electron beams

Question 53

can penetrate the cells very well but require too much time to be practical for killing microbes

Answer 53

x-rays

Question 54

shortest wavelength penetrate cells but require several hours to kill microbes

Answer 54

gamma rays

Question 55

wavelengths are greater than 1 nm

Answer 55

non-ionizing radiation

Question 56

does not penetrate cells but is suitable for disinfecting air, fluids and surface of objects

Answer 56

uv light

Question 57

most common chemical method of microbial control

Answer 57

phenols and phenolics

Question 58

- denatures proteins and disrupts cell membranes - remain active for a long time - commonly used in health care, labs, and homes

Answer 58

phenols and phenolics

Question 59

- denature proteins and disrupt cytoplasmic membranes - more effective than soap in removing bacteria - evaporates rapidly - not effective against endospores

Answer 59

alcohols

Question 60

why is alcohol advantageous and disadvantageous

Answer 60

long enough to kill microbes but not long enough to damage cells of skin

Question 61

- damages enzymes through oxidation - gain an electron when they react with another molecule - one electron short of filling their last electron shell

Answer 61

halogens

Question 62

examples of halogen

Answer 62

iodine tablets or topical use

Question 63

kill microbes by oxidizing enzymes, damages their structure and disrupt their function

Answer 63

oxidizing agents

Question 64

common oxidizing agents

Answer 64

peroxides, ozone, and peracetic acid

Question 65

an effect sporocide used to sterilize medical equipment

Answer 65

peracetic acid

Question 66

destroys endospores

Answer 66

sporocide

Question 67

what is used to sterilize drinking water

Answer 67

ozone treatment

Question 68

surface active chemicals that reduce surface tension of solvents to make them more effective at dissolving solutes

Answer 68

surfactants

Question 69

specifically target bacteria cells, work by disrupting cell membrane, used commonly in disinfectant wipes

Answer 69

quatenary ammonium compounds

Question 70

excellent for denaturing proteins, bacteriostatic and fungistatic

Answer 70

heavy metals

Question 71

controls algal growth

Answer 71

copper

Question 72

can remove prions on medical instruments

Answer 72

prionzyme