Bacteriology Flashcards
Cell wall
acts as a _______ to protect cell contents from external environment
maintains cell ________ in a ____ environment
contributes to sensitivity to certain ________ and the _____ system (antibodies, phagocytes)
Barrier
osmotic pressure; hypotonic
antimicrobial agents (penicillin)
immune
Cell wall determines reactivity to Gram stain
T/F
T
Gram positive cell wall
-peptidoglycan makes up ____% of the cell wall
-Techoic acid – polysaccharide, ____, is Important for ________ of some bacteria
60-90
antigenic
serologic identification
If peptidoglycan is digested away from the cell, gram positive cells lose their cell walls and become _______.
protoplasts
Protoplasts must be maintained in ______ solutions in order to survive.
isotonic
Gram negative cell wall
-A unique outer cell membrane that excludes all hydro____ molecules
This protects the bacteria from the action of _______ and ______ of the gut
It also contain (narrow or wide?) , restrictive protein channels called ____ which permits passage of (low or high?) molecular weight hydro___ molecules.
phobic
bile salts and toxins
Narrow ; porins; low ; philic
Large antibiotic molecules penetrate the outer membrane of gram negative bacteria (slowly or rapidly?) ( _______ )
Slowly
antibiotic resistance
Endotoxin/______ can trigger ______ and _______ in gram negative infections
Lipid A
fever and septic shock
Flagella
Are long filaments extending from the _________, which enable them to move in their environment.
they are built of _____ and are strongly ______.
The _______ are important targets of protective antibody response
cell surface
proteins
antigenic
H antigens
The flagella may be
polar -_______________
lophotrichous - ____________
amphitrichous:_______________
peritrichous - _____________
single cell, restricted to the pole
tuft at one pole
one or more flagella at both ends of the cell
distributed over the cell surface
Flagella can help in identifying certain types of bacteria e.g, _____ species show a rapid ‘swarming’ type of growth on solid media.
Proteus
CAPSULE
A gelatinous ________ and/or ______ outer covering
It may be firmly attached or loosely attached as a ______ ,Within which many cells can come together to form a ______, which may protect them from antibiotics and toxins
polysaccharide; polypeptide
slime layer
biofilm
Capsule can protect bacteria from phagocytosis by immune cells
T/F
T.
Capsule Permit bacteria to adhere to cell surfaces and structures
T/F
With examples
T
medical implants, catheters and so on.
Adherence is an important first step in _________ and sometimes leads to ______.
colonization
disease
Capsules can be a source of nutrients and energy to microbes.
T/F
T
Streptococcus mutans, which colonizes _____, ferments the ____ in the capsule and the _______ contribute to the resulting _______
teeth
sugar
acid byproducts
tooth decay.
Capsules don’t Prevent cell from drying out ( ________ )
T/F
F
desiccation
Polysaccharides from certain capsules is antigenic and can elicit production of _______ Included in ______
protective antibodies
vaccines
Plasmids replicate dependent on the chromosome
T/F
F
Plasmids replicate independently of the chromosome
Plasmids carry genes that are not essential for _____ but may give some advantage to an organism e.g they can carry genes for ________ and _______
cell survival
antibiotic resistance and toxin production.
Pili(___) project from the ______
Fimbriae
cell wall
Which are more rigid
Pili or flagella
Pili are more rigid than the flagella.
Pili function in _____________
(act as ______)
attachment to host cells
adhesins
Pili prevent phagocytosis
T/F
T
