Control Of Microbial Growth

Question 1

Sterilization

Answer 1

Killing off every living organism example hospital

Question 2

Disinfection

Answer 2

Destruction of all infectious organisms not sterile used on non-living material harsh

example bleach

Question 3

Antisepsis

Answer 3

Disinfection of living tissue not sterile

example ethanol

Question 4

Sanitation

Answer 4

Removal of enough micro organisms to prevent problems

Question 5

Explain the difference between some thing that is bacteriocidal versus some thing that is bacteriostatic

Answer 5

Bacteriocidal is going to kill the organism lethal

bacteria static is going to pause the organism example refrigeration stop the growth but without killing

Question 6

What are two factors that determine how long it takes to sterilize a sample

Answer 6

Initial population and rate of death

Question 7

What is logarithmic growth and death

Answer 7

A pattern way of growth and death

example a bag salad has 1 million subs per bag of salad when it’s washed one time 99% is removed 10,000 Cells left second wash 100 cells left and third wash one cell is left

Question 8

Which two mechanisms typically kill micro organisms and what are some techniques that are used for each

Answer 8

Physical
examples UV light and auto clave heat and pressure

Chemical
examples bleach ethanol

Question 9

Describe the five methods of physically limiting microbial growth

Answer 9

Heat

pressure

Filtration

desiccation

radiation

Question 10

Which methods are bacteriocidal

Answer 10

Boiling, auto clave, pasteurization, incineration

heat and pressure.

Radiation

Question 11

Which method or bacteriostatic

Answer 11

They’ll tradition, refrigeration, he’s trying, high salts

Filtration desiccation

Question 12

Which two bacterial genre may survive boiling and why/how much they survive this method of controlling growth

Answer 12

Endospores not a high enough heat, clostridium botulism

Question 13

Describe the general process of pasteurization explain what types of organisms might withstand pasteurization

Answer 13

72°C for 15 seconds and then rapidly cool this denatures the proteins, thermophiles with stand but they cannot live with a mesophile

Question 14

What technique do scientist used to sterilize media, tubes, or ways in which infectious agent may not be neutralized by this technique?

Answer 14

Auto clave, prions/viruses

Question 15

Explain the difference between ionizing and non-ionizing radiation

Answer 15

Ionizing has more energy and is more damaging to the living cell

Question 16

Name One benefit and one drawback of using UV light to inhibit microbial growth

Answer 16

Kill the top layer and surface deContamination

Poor Penetration

Question 17

Name one benefit and one drawback of these in GammaRay to inhibit microbial growth

Answer 17

Cleans and can be used on food plastic kills with no radio active residue

Extremely highly reactive and higher radiation

Question 18

Hydrogen peroxide

Answer 18

Oxidative damage to living organisms slows down the healing caused by the tissue damage catalase can’t keep up but harmless and it’s decomposition

Question 19

Phenol

Answer 19

Disrupts plasma membrane, D natures proteins hydrophobic

Question 20

Ethanol/isopropyl alcohol

Answer 20

Disrupts the plasma membrane and candy nature Protein non envelopes virus Endospores not impacted

Question 21

Quaternary ammonium compounds quats

Answer 21

Surfactants reduce the surface tension and Disrupt plasma membrane. Fine catatonic affective agent with gram-positive hydrophobic and hydrophilic less

affective on mycobacterium because of wax permanently positively charged

Question 22

Aldehydes

Answer 22

Strong enough to actually sterilize chemically crosses links and fix it proteins stops life example formaldehyde

Question 23

Alkylating agents

Answer 23

Reactive proteins and nucleic acid’s to cross-link bacteriocidal toxic to living organisms gas sterilants useful for tricky places

Question 24

Halogens

Answer 24

Bacteriocidal disrupts protein membrane hydrophilic oxidative damages steals electrons

Example: fluorine, bromine, chlorine , iodine

Question 25

Describe the type of compounds that inhibit the growth through oligodynamic action

Answer 25

Antimicrobials silver copper zinc mercury are toxic traits to micro organisms tiny amounts of Meadows prevent growth and inhibits enzymes example of silverware

Question 26

An island off the coast of Scotland was used for testing bacillus and taxis as a germ of warfare agent during World War II frequently fatal disease of livestock in humans also farms endospores. You have been hired by the British government to decontaminate the island. The problem is that the entire surface of the island is full of endospores to the depth of 12 inches given the options of chemical approach and physical approach how do you go back to decontaminating the topsoil the island island

Answer 26

Chemical method aldehydes

Strong enough to actually sterilize chemically, cross links protein fixates to stop life