Test 3 Chapter 13 Study Guide

Question 1

Biosafety Level 1 (BSL-1)

Answer 1

Handling Pathogens that do not cause disease in healthy humans

Question 2

Biosafety Level 2 (BSL-2)

Answer 2

Handling Moderatly Hazardous agents.

Question 3

Biosafety Level 3 (BSL-3)

Answer 3

Handling microbes in safety cabinets. Double Door system, negative pressure

Question 4

Biosafety Level 4 (BSL-4)

Answer 4

Handling microbes that cause sever or fatal disease

Question 5

Sterilization

Answer 5

Complete 100% removal of vegetative cells, endospores, and viruses

Question 6

Aseptic Technique

Answer 6

Prevents contamination of sterile surfaces

Question 7

Commerical Sterilization for food

Answer 7

Not truly sterile because many non-pathogenetic organisms survive. Goal is to get rid of pathogens.

Question 8

Disinfection

Answer 8

removes MOST microbes from the SURFACE OF AN OBJECT

Question 9

Antiseptics

Answer 9

Removes MOST microbes from LIVING Tissue

Question 10

Degerming

Answer 10

SCRUBBING of LIVING TISSUE with a mild chemical (handwashing)

Question 11

Sanitization

Answer 11

cleansing of fomites enough to achieve levels deemed safe for public health

Question 12

Bacteriocides

Answer 12

Kills bacteria

Question 13

Bacteriostatic

Answer 13

Doesn’t kill bacteria just stops growth

Question 14

Fungicides

Answer 14

Kills fungi

Question 15

Fungistatic

Answer 15

Doesn’t kill fungi, just stops growth

Question 16

Viricidal

Answer 16

Makes viruses non-infectious

Question 17

D-Value

Answer 17

Amount to kill 90% of the population. Regardless of size of the population.

Question 18

Effects of High Temperatures on Bacterial Growth

Answer 18

Denature proteins. Interfere with integrity of cytoplasmic membrane and cell wall. Disrupt structure and function of nucleic acids

Question 19

Thermal Death Point

Answer 19

Lowest temperature that kills all cells in broth in 10 min. Does not include endospores

Question 20

Thermal Death Time

Answer 20

Time to sterilize volume of liquid at set temperature. Does include endospores

Question 21

3 microorganisms that can survive boiling

Answer 21

Endospores, Protozoan cysts, some viruses(?)

Question 22

Boiling time and sterilization

Answer 22

Boiling time is critical for proper sterilization. Higher elevation requires longer boiling time.

Question 23

Boiling Time can’t kill

Answer 23

No matter how long you boil you wont kill endospores or protozoan cysts

Question 24

Autoclaving

Answer 24

combination of moist heat and pressure

Question 25

Autoclaving Process

Answer 25

Pressure is applied to boiling water. This prevents steam from escaping. Boiling temperature increases as pressures increase

Question 26

Autoclave Conditions

Answer 26

121oC, 15 psi, 15 minutes

Question 27

Pasteurization Isn't sterilization

Answer 27

Pasteurization is not sterilization because heat-tolerant microbes will survive

Question 28

Flash Pasteurization

Answer 28

Most common, High temperature short time, Not sterilization, just pathogens

Question 29

Ultrahigh-Temperature pasteurization

Answer 29

Sterilization. Coffee creamer. Boxed milk.

Question 30

Cold environments and microbes

Answer 30

decrease microbial metabolism, growth, and reproduction. Refrigeration halts growth of most pathogens.

Question 31

slow freezing vs rapid freezing

Answer 31

Slow freeze allows ice crystals to form in the bacterial cell. Quick freeze might put the microbes in a vegetative state.

Question 32

Lyophilization (freeze-drying)

Answer 32

used for long-term preservation of microbial cultures. Prevents formation of the ice crystals in slow freezing that would damage the cells.

Question 33

Desiccation (drying)

Answer 33

inhibits growth due to the removal of water.

Question 34

Osmotic Pressure

Answer 34

High concentrations of slat or sugar in foods to inhibit growth.

Question 35

Cells in hypertonic solution of salt or sugar

Answer 35

Lose water

Question 36

Ionizing radiation

Answer 36

ejects electrons from atoms to create ions

Question 37

Ionizing radiation on Microbes

Answer 37

Ions disrupt hydrogen bonding, oxidize double covalent bonds, and create hydroxyl radicals. Gamma rays penetrate well but require hours to kill microbes. X-rays require long time to kill microbes. Not practical microbe control

Question 38

Joseph Lister

Answer 38

first to use antiseptic to help prevent surgical and post-surgical infections

Question 39

Phenolics Affect

Answer 39

Denatures proteins, disrupt membrane, Effective in presence of organic matter

Question 40

Phenolics Examples

Answer 40

Listerine, Lysol, Triclosan

Question 41

Heavy Metals Affect

Answer 41

Binds to proteins and inhibit enzymatic activity. Not selective to microbes

Question 42

Heavy Metals Examples

Answer 42

Mercury, Silver, Copper, Nickle, and Zinc

Question 43

Halogens Affect

Answer 43

Oxidation and destabilization of macromolecules

Question 44

Halogens Example

Answer 44

Iodine (betadine) chlorine, fluorine

Question 45

Alcohols Affect

Answer 45

Denature proteins and disrupt cell membranes

Question 46

Alcohols Acts as A

Answer 46

Bactericidal, Fungicidal, Viricidal for enveloped viruses only

Question 47

Surfactants Affect

Answer 47

Lower surface tension of water - amphipathic. Can make lipids water soluble

Question 48

Surfactants Examples

Answer 48

Soaps and detergents. Cationic Detergents. Quats

Question 49

Bisbiguanides Affect

Answer 49

Cationic antiseptics, can be used on skin, disrupts cell membranes

Question 50

Bisbiguanides Examples

Answer 50

Chlorhexidine

Question 51

Alkylating Agents Affect

Answer 51

Inactivate enzymes and nucleic acids

Question 52

Alkylating Agents Examples

Answer 52

Formaldehyde - Carcinogen. Ethylene Oxide - Sterilize surgical equipment that can't be autoclaved

Question 53

Oxidizing Agents Affect

Answer 53

Kill by oxidation of microbial enzymes. Peroxide, ozone, and peracetic acid.

Question 54

Oxidizing Agents Example

Answer 54

High-level disinfectants and antiseptics.

Question 55

Hydrogen peroxide

Answer 55

Can disinfect and sterilize surfaces. Not useful for treating open wounds due to catalase activity.