Microbiology CH 9 Flashcards
What are the 4 ways to control microbes and are they physical or chemical processes?
- Sterilization - Both
2.Decontamination/Sanitization - Chemical - Disinfection - Physical
- Antisepsis/Degermation - Physical
Define Sterilization
Elimination of all life (protists, bacteria, viruses, dormant/vegetative cells)
What is the most broad strategy for “Control” called?
Sterilization
What ‘Control’ is a chemical process than ONLY kills cells and can be harmful to tissue like skin?
Disinfection
Define Disinfection
Destruction of vegetative/active organisms on a surface that does NOT remove the cells
Define Decontamination
Removal of vegetative cells and other potentially hazardous materials from a non-biological surface
What is the process of removing vegetative cells from a potentially hazardous surface?
Decontamination/Sanitization
Define Antisepsis/Degermation
Removal of vegetative cells on BIOLOGICAL surfaces
What is the process of removing vegetative cells on biological surfaces?
Antisepsis/Degermation
What is the word for killing microbes?
Bactericidal
What is the word for stopping microbes without killing them?
Bacteriostatic
What dehydrates a cell and causes it to shrivel and completely die off due to losing moisture?
Dry Heat
Define Incineration
Cells completely oxidize and turn to ash due to enough dry heat
What materials are better controlled with moist heat?
Liquids
What materials are better controlled with dry heat?
Powders
What does moist heat cause proteins to do?
Denature
What does denaturing do?
Causes proteins to lose its 3D shape. The active site changes its stucture and loses ability to function
What are the 3 Moist Heat Methods?
- Boiling<br></br>2. Pasteurization<br></br>3. Autoclaving
What is a method for disinfection of water or of surfaces that can tolerate being submerged in water?
Boiling
How long and at what temperature kills most vegetative cells?
30 minutes at 100C
Define boiling
Method of disinfection for water or surfaces that can tolerate being submerged in water
Define Pasteurization
Use of less-than-boiling heat to partially disinfect liquids that would be damaged by boiling
What does Pasteurization do?
Kills spoilage organisms and pathogens
What is the word for using less-than-boiling heat to partially disinfect liquids that would be damaged by boiling?
Pasteurization
Define Autoclaving
Use of high pressure to raise the steam point of water, allowing steam to exist at 121C and kill more (ideally ALL) things, including endospores<br></br>
What is using high pressure to raise steam to the point of water in order to kill more things called?
Autoclaving
What is it called with flames are used to expose organisms to temperatures so high they completely oxidize and turn to ash?
Incineration
What temperatures kills vegetative cells and spores respectively?
80C and 120C
What can cold temperature control be defined as?
Microbiostatic
Define lyophilization
Process of ‘freeze-drying’ cells to keep them alive long-term
What is the process of freeze-drying cells to keep them alive long-term called?
Lyophilization
Define Radiation
Use of electromagnetic waves to damage cellular components
What is the word for usage of electromagnetic waves to damage cellular components?
Radiation
What does ionizing radiation do?
Creates charged particles in the cell, damaging it all over the place
What does non-ionizing radiation do?
Creates mutations in DNA
What forms when two thymine bases are next to each other?
Thymine Dimers (covalent bond)
What leads to errors in DNA replication?
Thymine Dimers
What do Thymine Dimers cause?
Errors in DNA replication
What do chemical methods of control target?
Specific structures or compounds within the cell
What may need to be controlled using different chemicals so that chemical methods are effective?
Specific surfaces or environments
Where on the periodic table are Halogens found?
Group 17
What are the two major halogens used as part of chemical control?
Chlorine and Iodine
What reacts with water to create Hypochlorous Acid (HOCl)?
Bleach
What does bleach do?
Denatures enzymes and disrupts cellular function
What does iodine do?
Disrupts metabolic enzymes and can denature proteins
What do halogens target?
All living cells including endospores with long exposure
What are oxidizing agents?
Chemical compounds that are highly electronegative and are able to steal electrons from other compounds
What can form free radicals (OH-) which can react with many compounds in the cell, including DNA?
Hydrogen Peroxide (H2O2)
What does Hydrogen Peroxide target?
Endospores or living cells that are not catalase-positive
Low concentrations of hydrogen peroxide can…?
Kill obligately anaerobic bacteria in patients with topical application
High concentrations of Hydrogen Peroxide can…?
Be used to sterilize delicate instruments that cannot be sterilized with heat
What are phenolic compounds?
Aromatic compounds usually containing at least a hydroxyl group
What is Phenol?
Benzene ring with a hydroxyl on it
What two phenolic compounds have been used extensively in antibacterial soaps?
Triclosan and Triclocarban
What do Triclosan and Triclocarbon do?
Disrupt cell walls, cell membranes, and proteins
What phenolic compounds have been implicated as potentially toxic to humans and potentially damaging to the human microbiome?
Triclosan and Triclocarban
What do phenolic compounds target?
Some bacteria, fungi, and viruses
What are Alcohols?
Short carbon molecules containing a hydroxyl (OH) functional group
What ingredients are known as rubbing alcohol?
Ethanol and Isopropanol
What happens at high concentrations (>50%) with alcohols?
Cell membranes dissolve, cell surface tension is dissolved, and cell structures are compromised
What is the downside of alcohols?
Alchohols evaporate quickly, meaning anything that can survive short-term will probably survive
What do alcohols target?
Most bacteria, fungi, and viruses
What are heavy metals?
Compounds containing metals such as mercury and silver
What heavy metal can be used in topical germicidal creams?
Silver Nitrate (AgNO3)
What do heavy metal antiseptics do?
React with specific functional groups in proteins to disrupt their functions
What is the risk of using heavy metals (specifically Silver Nitrate)?
It may react with functional groups in proteins and disrupt their functions within healthy tissues
What do heavy metals target?
Some bacteria, fungi, viruses
What are detergents?
Usually amphipathetic molecules that react with surface of the cell, but also hydrophobic regions of cell membrane
What is the active ingredient used in Formula 409?
Quarternary Ammonium
What kind of ion is Quarternary Ammonium and what does it do?
Positively-charged ion that disrupts cell membranes
What detergent is regularly used in soaps and shampoos?
Sodium lauryl sulfate
What charge is sodium lauryl sulfate?
Negatively-charged ionic compound
What is a surfactant?
A substance that disrupts membrane surface tension
What does detergent target?
Certain bacteria, enveloped viruses, and fungi
Myobacterium are _______ from detergents
Innately protected
What can kill endospores?
Silver Nitrate, High Concentration of Hydrogen Peroxide, Autoclaving, and Iodine <br></br>*Note: Probably another too that I forgot about but these are the confusing ones
