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Medical Microbiology (Exam 2)

Terms in this set (51)

Which of the following is NOT a characteristic of biofilms?
A. Antibiotic Resistance
B. Hydrogel
C. Iron Deficiency
D. Quorum Sensing
A. Antibiotic Resistance
During the lag phase, there is ______ or ______ in the number of cells, but metabolic activity is ______.
Little, no change, high
The requirement for microbial growth are both ______ and _______.
Physical and Chemical
A microbe that is classified as "cold-loving" is called?
Psychrophile
A microbe that is classified as "moderate-temperature loving" is called?
Mesophile
A microbe that is classified as "heat-loving" is called?
Thermophile
The growth of a population refers to an increase of what?
The number of cells
Halophiles can tolerate a high concentration of what?
A high concentration of salt
Describe an Obligate Aerobe.
An organism that requires oxygen to live.
Describe an Obligate Anaerobe.
An organism that does not require oxygen and is killed in the presence of oxygen.
Describe a Facultative Anaerobe.
An organism that can grow with or without oxygen.
Describe a Microaerophile.
An organism that requires very low amounts oxygen to grow.
Describe an Aerotolerant Anaerobe.
An organism that does not use oxygen, but it's not affected by its presence.
Aerobes, Facultative Anaerobes, and Aerotolerant Anaerobes must have what?
They must have the enzymes Superoxide dismutase and catalase.
What pH levels do microbes grow best between in?
6 to 8 (Powerpoint) or 6.5 to 7.5 (Textbook)
Acidophiles are known to love what, while Alkalinophiles prefer?
Acid loves low pH (tolerant to acidity), while Alka prefer high pH.
An organism that has peroxidase and superoxide dismutase but lacks catalase is most likely an:
a. Aerobe
b. Aerotolerant anaerobe
c. Obligate anaerobe
b. Aerotolerant anaerobe
Describe Binary Fission
A Prokaryotic cell reproduction by division into two daughter cells.
Describe what happens during Plasmolysis.
The loss of water from a cell in a hypertonic environment.
What type of organism requires an organic carbon source?
Hetertroph
What type of organism uses carbon dioxide as its carbon source?
Autotroph
The term Trace Elements refers to what?
a. the elements of CHONPS
b. vitamins
c. nitrogen, phosphorus, and sulfur.
d. small mineral requirements.
e. toxic substances.
b. vitamins.
An organism that uses light as its energy source and carbon dioxide as its carbon source.
Photoautotroph
An organism that uses an inorganic chemical as an energy source and carbon dioxide as a carbon source.
Chemoautotroph
An organism that uses organic molecules as a source of energy and carbon source.
Chemoheterotrophs.
Passive Transport requires ______.
No ATP.
Concentration gradient is used.
Active Transport requires _______.
Requires ATP.
Substance move against concentration gradient.
Bacteria grow in number by ______ ______.
Binary Fission
Which one of the following temperatures would most likely kill a mesophile?
a. -50 degrees C
b. 0 degrees C
c. 9 degrees C
d. 37 degrees C
e. 60 degrees C
b. 0 degrees Celsius
Define Sterilization
The process that destroys all viable microorganisms and resistant forms of life.
What is the difference between Microbicidal and Microbistasis?
-cide = to kill, -stasis/static = to stand still
Bactericide is a chemical that ______ bacteria.
Destroys/kills
Bacteriostatic is an agent that _______ the growth, but does not _______.
Prevents, destroy
This is a physical or chemical process that reduces vegetative pathogens.
Disinfection
What is a chemical agent that is applied to the body to destroy or inhibit pathogens?
Antiseptics
What is a difference between Sanitization and Degermination?
Sanitization = requires use of a soap or other similar agents to reduce the microbial levels.
Degermination = requires scrubbing of the skin to mechanically reduce microbes.
Which of the following does not kill endospores?
a. autoclaving
b. incineration
c. hot air sterilization
d. pasteurization
e. all of the above kill endospores
d. pasteurization
What is an autoclave?
A special device that can regulate the pressure and temperature.
The process of mild heating to kill particular spoilage microorganisms or pathogens.
Pasteurization
What type of radiation has deep penetrating powers and breaks DNA into fragments?
Ionizing radiation
This type of radiation causes abnormal bonds in DNA that prevent replication; also can't penetrate deeply.
Non-ionizing radiation
Which of the following is most effective for sterilizing a plastic Petri dish?
a. chlorine
b. ethylene oxide
c. glutaraldehyde
d. autoclave
e. nonionizing radiation
b. ethylene oxide
*Often used to sterilize medical and pharm. products that cannot support conventional high temp. steam sterilization.
Out of all the Halogens which two are good disinfectants?
a. fluorine & chlorine
b. bromine & astatine
c. chlorine & iodine
d. fluorine & astatine
e. iodine & bromine
c. chlorine & iodine
A powerful disinfectant that if given time can act like a sterilizing agent.
Aldehyde
Ex: glutaraldehyde
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is:
a. disinfection
b. sterilization
c. antisepsis
d. sanitization
e. degermation
C. antisepsis
The lowest temperature at which all the microbes in a sample are killed in 10 minutes.
Thermal Death Point (TDP)
The length of time required to kill all bacteria in a sample at a given temperature.
Thermal Death Time (TDT)
The length of time in which 90% of bacterial population will be killed at a given temperature.
Decimal Reduction Time (DRT)
What is the difference between Heterotroph and Autotroph?
Hetero = Depends on other life forms such as organic molecules.
Auto = They are self-feeders.
How could RNAi be used as a gene silencer?
RNAi stops gene expression at transcription by using a short interfering RNA to make double-stranded helix.
Why can translation begin before transcription is complete prokaryotes but not in eukaryotes?
The mRNA is produced in the cytoplasm in prokaryotes, the start codons of an mRNA being transcribed are available to ribosomes before the entire mRNA molecule is even made.
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