ch 7

Question 1

autoclave

Answer 1

steam heat under pressure- steam must contact item’s surface

Question 2

pasteurization

Answer 2

reduce, not sterilize spoilage organisms
high temp for a short time
-ultra past.- very high temp for even shorter time

Question 3

dry heat/ flamming

Answer 3

kills by oxidation

Question 4

biocide/germicide

Answer 4

kills microbes

Question 5

bacteriostasis

Answer 5

inhibiting, not killing microbes

Question 6

asepsis

Answer 6

the absence of significant contamination

Question 7

sterilization

Answer 7

removing all microbial life

Question 8

disinfection

Answer 8

removing pathogens

Question 9

degerming

Answer 9

removing microbes from a limited area

Question 10

sanitization

Answer 10

lowering microbial counts on eating utensils

Question 11

filtration

Answer 11

decreases number of microbes based on size of microbes, used when you can’t use heat

Question 12

low temp

Answer 12

inhibits microbial growth- refridgeration, deep freeze, lyophilization

Question 13

high pressure

Answer 13

denatures proteins

Question 14

desiccation

Answer 14

prevents metabolism

Question 15

osmotic pressure

Answer 15

causes plamolysis

Question 16

microbial death curve

Answer 16

kill 90%

Question 17

how does radiation kill cells

Answer 17

damages the DNA- ionizing and nonionizing

Question 18

List the 4 factors related to effective disinfection

Answer 18

1. concentration of disinfectant
2. organic matter
3. pH
4. time

Question 19

interpret the results of the disk-diffusion method

Answer 19

will have a zone of inhibition- does not kill microbes, just slows the growth

Question 20

list the most to least resistant microbes (1-5)

Answer 20

1. prions
2. endospores of bacteria
3. mycobacteria
4. cysts of protozoa
5. vegitative protozoa

Question 21

list the most to least resistant microbes (6-10)

Answer 21

6. gram-neg bacteria
7. fungi (including spores)
8. vius w envelopes
9. gram pos bacteria
10. virus w lipid envelopes

Question 22

which is best way to get rid of microbes

Answer 22

sterilization- moist heat

Question 23

thermal death point

Answer 23

lowest temp at which all cells in a culture are killed in 10 min

Question 24

thermal death time

Answer 24

time during which all cells in a culture are killed

Question 25

decimal reduction time

Answer 25

min to kill 90% of a population at a given temp

Question 26

triclosan

Answer 26

a bisphenol (disrupts plasma membranes)