Ch 5 Microbial Control

Question 1

What is sterilization?

Answer 1

Killing of all living organisms

Question 2

What is disinfection?

Answer 2

Killing or removal of pathogens from inanimate objects

Question 3

What is antisepsis?

Answer 3

Killing or removal of pathogens from the surface of living tissues

Question 4

What is sanitation?

Answer 4

Reducing the microbial population to safe levels

Question 5

True or False: Microbes die on a positive exponential curve

Answer 5

Fase, negative exponential curve

Question 6

What is the decimal reduction time (D-value)?

Answer 6

The length of time it takes a condition to kill 90% of the population

Question 7

How do you preserve microbes?

Answer 7

Cold temperatures

Question 8

How do you kill microbes?

Answer 8

High temperatures

Question 9

How do you kill spores and thermophiles?

Answer 9

Combination of high pressure and temperature

Question 10

High temperature in the autoclave will destroy which materials?

Answer 10

Polystyrene, non-borosilicate glass, and styrofoam, biological substances

Question 11

Pasteurization: temperature combinations

Answer 11

LTLT: 63 C for 30mins
HTST: 72 C for 15secs
UHT: 135 C for 2 secs

Question 12

Can you kill microbes with ultraviolet light?

Answer 12

Yes, but only for surface sterilization

Question 13

What are gamma rays used for?

Answer 13

Irradiating foods and heat-sensitive items

Question 14

Bacteria with greatest ability survive radiation of any known organism

Answer 14

Deinococcus radiodurans

Question 15

What is filtration?

Answer 15

Filters with a pore size of .2um can remove microbes from solutions

Question 16

Most effective commercial disinfectants are most active between what percentages?

Answer 16

60%-90%

Question 17

How do you kill spores?

Answer 17

With bleach

Question 18

What are antibiotics?

Answer 18

Chemical compounds synthesized by one microbe that kill or inhibit growth of other microbial species

Question 19

What do antibiotics target in the cell?

Answer 19

Protein synthesis, DNA replication, cell membranes

Question 20

What is biocontrol?

Answer 20

The use of one microbe to control the growth of another microbe

Question 21

Example of biocontrol

Answer 21

Probiotics, they restore balance in the intestines

Question 22

What is phage therapy?

Answer 22

Treats infectious diseases with a virus targeted to the pathogen