chapter 3 (a) Flashcards
(152 cards)
axial filament is another term for
endoflagellum
A periplasmic flagellum found in some spirochete bacteria is called a(n)
____ filament.
axial
Which appendages provide attachment points or channels, rather than motility? More than one answer may be correct.
a. flagella
b. axial filaments
c. pili
d. fimbriae
e. nanotubes
c, d, e
describe peptidoglycan structure
in gram positive cells: what two acids do peptidoglycan contain?
Contains teichoic acid and lipoteichoic acid
what do teichoic acid and lipoteichoic acid do
- Function in cell wall maintenance and enlargement
- Contribute to the acidic charge on the cell surface
in gram positive cells
in gram -negative cell walls how thick is the peptidoglycan layer ?
1 - 3mm
steps in a gram stain?
t/f only some bacterial cells can be gram stained
MOST ALL BACTERIA because most all have a cell wall
what is the most important stain
gram stain, most all bacteria can be stained because they contain a cell wall
Mycobacterium and Norcardia are examples of
acid fast bacteria
contain peptidoglycan and stain gram-positive, but bulk of cell wall is composed of unique lipids
acid fast bacteria Mycobacterium and Norcardia
where is Mycolic acid found
Found in the cell walls of acid-fast bacteria
what is Mycolic acid
Very-long-chain fatty acid
what does mycolic acid do
Makes bacteria highly resistant to certain chemicals and dyes and contributes to the pathogenicity of bacteria
Exhibit unusual adn chemially distinct cell walls
Archaea
some ______ have cell walls composed entirely of polysaccharides others have cell walls made of pure protein
archaea
____ lack true peptidoglucan structure
archaea cell wall
T/F ALL archea have a cell wall
some lack a cell wall entirely
T/F Mycobacterium adn Norcardia stain gram negative
False, they contain pepidoglycan and stain gram + but bulk of cell wall is compose of unique lipids (mycolic acid)
genus that naturally lack a cell wall
Mycoplasmas
sterols in this genus cell membrane stabilize the cell against lysis
Mycoplasmas ( no cell wall)
L forms
some bacteria that naturally have a cell wall but lose it during part of life cycle due to mutiations etc
t/f L forms play in a role in resistant antibiotics
true, role in persistent infections, no cell wall to kill