Chapter 4 Flashcards
(28 cards)
What is the function of endospores?
they allow a cell to survive environmental changes by producing a dormant period with no growth
What is the morphology of a bacteria with axial filament?
corkscrew shape with the filament wrapping around the cell
What is the morphology of streptococci?
a cell with a chain of spherical shapes
The terms “run” and “tumble” are generally associated with
movements of the cell in response to attractants or repellents
You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell…
has a cell wall.
Fimbriae and pili differ in that
pili are used for transfer of DNA and motility
What type of cell wall possesses lipid A and endotoxins responsible for symptoms associated with infection?
gram-negative
Which cell wall is resistant to many antibiotics?
gram-negative
Which cell wall contains teichoic acids?
gram-positive
How do spirochetes and spirilla differ?
Spirilla have external flagella, but spirochetes have axial filaments.
What is the structure of DNA found in most bacterial cells?
it is circular in structure
In bacterial ribosomes, a small 30S subunit and a large 50S subunit come together to produce the functional 70S ribosome. Why isn’t it an 80S ribosome?
S is referring to the sedimentation rate based on size, weight, and shape of a particle, and the values aren’t necessarily additive
What is a biofilm?
large aggregations of bacterial cells that share a common glycocalyx called an extracellular polymeric substance
What is the function of biofilm?
it provides a shared substance that can facilitate communication among cells, and allow inhabitation of otherwise uninhabitable environments
What role does biofilm play in disease?
it helps pathogenic bacterial infections adhere to epithelial tissues and protect pathogens from phagocytosis by host immune cells
Describe the lophotrichous flagellar arrangement
many flagella attached at one pole
Describe monotrichous flagellar arrangement
one flagella attached at one pole
Describe peritrichous flagellar arrangement
flagella attached all over the cell
Describe amphitrichous flagellar arrangement
many flagella attached at both poles
What is the function of the cell wall?
cell protection and structural stability
What is the main role of an endospore?
dormancy
What is the role of fimbriae?
attachment to surfaces
What is the role of flagella?
motility
What is the role of glycocalyx?
protection from phagocytes
