- StudyBlue
- Texas
- Texas Tech University
- Microbiology
- Microbiology 3400
- Moss
- MICRO 7 (2)
MICRO 7 (2)
Microbiology 3400 with Moss at Texas Tech University
About this deck
By: Stefanie Landeck
Created: 2010-10-13
Size: 37 flashcards
Views: 23
Created: 2010-10-13
Size: 37 flashcards
Views: 23
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy
Kathy
Sign up (free) to study this.
Sterilization
kills all cells present
Disinfection
reduces number to harmless level
Antiseptic
kills microbes on living tissue
Bactericide
kills microbes
Bacteriostatic agent
inhibits growth
Viricide
inactivates viruses
Fungicide
kills fungi
Sporocide
kills spores
Thermal death point
minimum temp required to kill microorganisms in 10 minutes
Thermal death time
time it takes to kill microorganisms at a certain temperature
What are some ways to physically control microbial growth
•Heat
•Cold
•Radiation
•Filtration
•Drying
•Osmotic Strength
Dry heat sterilization
Speeds up the oxidation of proteins with a hot air oven or open flame for some objects (inocultating loop etc)
Wet heat sterilization
Denatures proteins and destroys structure using either boiling water or an autoclave
How does boiling water sterilize?
Destroys vegetative cells, inactivates some viruses, not effective in killing all spores
How does an autoclave sterilize?
- Autoclave uses pressure to raise the boiling point of water to above 121°C.
- This temperature is effective in killing spores, disrupting nucleic acid in viruses
Pasteurization
Decreases numbers of microorganisms in milk, dairy products, wine, and beer but does not achieve sterility but kills pathogens causing human diseases
Flash method of pasteurization
heat milk to 71.6°C for 15 seconds
Holding method of pasteurization
heat milk to 62.9°C for 30 minutes
UHT processing of pasteurization
raises temperature from 74°C to 140°C and then back down to 74°C in less than 5 seconds which makes it safe without refridgeration
Cold Method of controlling organisms
does not kill but can halt growth by slowing the rate of enzyme controlled reactions in microorganisms through refrigeration, freezing, drying, and freeze-drying
Lyophilization
`drying of material from the frozen state
What are the general types of radiation?
1. Ultraviolet light
2. Ionizing radiation
3. Microwave radiation
4. Strong visible light
Ultraviolet light radiation
most lethal form of radiation which has wavelengths from 40-390 nm
What is the most effective wavelength for killing microbes and what does it do?
200 nm; damages DNA and proteins and is ususally used in hospitals
Photoreactivation
repairs damage done by UV light radiation
What types of rays does ionizing radiation do?
x rays (.1-40 nm)
gamma rays (.001-1 nm)
Ionizing radiation is used to sterilize:
microorganisms and viruses in
- Foods (beef, poultry, fish, fruits)
- Laboratory and medical equipment (plastic)
- Pharmaceutical products
What happens under ionizing radiation?
Strips electrons from atoms creating ions, damages DNA, and produces peroxidases
How long are wavelengths used in microwave radiation?
1mm-1m
What must be present for microwave radiation to be effective?
water
How long are wavelengths in strong visible light?
400-700 nm
What does strong visible light do?
oxidizes light-sensitive molecules such as riboflavin and porphyrins
What is strong visible light effective against?
some bacteria and viruses, especially when used along with fluorescent dyes
Filtration pore sizes
.025-25 μm
Does filtration achieve sterilization?
no because viruses are not trapped by the filter
What is filtration useful for?
media, vitamin and antibiotic solutions, anything denatured by heat
What are the major antimicrobials?
null
About this deck
By: Stefanie Landeck
Created: 2010-10-13
Size: 37 flashcards
Views: 23
Created: 2010-10-13
Size: 37 flashcards
Views: 23
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy
Kathy