VTT 234 Final review Flashcards
(25 cards)
Define prokaryotes
Lake a nucleus and membrane bound organelles. These are bacteria
Define Eukaryotes
Have a true nucleus, usually molds.
What is an anaerobic environment
No oxygen
What is an aerobic environment
Needs oxygen
Name the four different bacterial shapes
Sphere (cocci), Rods (bacillus), Spirals (spirochetes)
What is normal flora?
Found on: skin, nasal, ears, digestive, genital/urinary tract, eyes, ears, mouth
What is ubiquitous?
Found everywhere, soil, water, food, atmosphere, vegetation.
Define an opportunistic pathogen
an organism that normally does not cause disease
Define an obligate pathogen
a bacteria that is never part of normal flora and causes disease
Define incubation period
period of time from the initial infection to when clinical signs/symptoms appear.
Define zoonosis
a disease that can be transmitted from animals to people.
Define endemic
an organism that remains in a certain geographical area.
Define epidemic
a sudden increase of disease cases
Define pandemic
epidemic that spreads trough populations over a vast region
Define gram +
Cells physically have a thicker cell wall.
The cell wall contains greater amounts of peptidoglycan.
Peptidoglycan acts as a barrier to decolorization.
Show as blue or purple
Define gram -
Cell wall is more complex.
Less peptidoglycan, more lipopolysaccharide allows the cell wall to become decolorized.
Show as red or pink
Catalase test
Performed on gram + bacteria
Positive- bubbling
Staphylococci will be positive
Streptococci will be negative
Potassium Hydroxide Test
KOH positive, Gram + = no mucus (because cell wall thicker)
KOH negative, Gram - = mucus
Define pathogenicity
Ability of a pathogen to produce an infectious dz (cause harm to the host)
Define virulence
The measure of degree of pathogensis
Also it’s ability to reproduce within the host
How can bacteria produce disease
Tissue invasion and toxin production
What is a Differential-Selective media type
It inhibits the growth of a particular type of organism while allow other types to grow and be distinguished from each other based on their metabolic activities.
What is a Enriched media type?
enhances the growth and/or the distinguishing characteristics of a particular group of organisms.
What is a Selective Enrichment media type?
enhances the growth of a particular type of organism while inhibiting the growth of others.
