Bacterial Cell Walls and Envelopes Flashcards
Where is the electron transport chain in bacteria?
on the inside of the cytoplasmic membrane
When talking about gram + and gram - with regards to cell walls and envelopes…
gram + = cell wall
gram - = envelope
cell wall= peptidoglycan
envelope= double membrane
Where are lipopolysaccharides and teichoic acids found?
lipopolysaccharides = gram -
teichoic acids = only in gram +
T/F: There are histones in bacteria
False!
No nucleus/histones in bacteria
What is the function of cell wall in bacteria?
to give it a rigid structure and shape
Why are bacteria so tough?
peptidoglycan/cell wall layer
T/F: bacteria cytoplasmic membrane has a selective permeability barrier
True
What is flagella and pili used for?
flagella for motility
pili for attachment/anchor
What’s the main difference in gram + vs. gram - ?
- gram + has a THICK peptidoglycan layer on outside of cytoplasmic membrane. stains purple
- gram - has thinner peptidogylcan in the periplasm space between cytoplasmic membrane and outer membrane (more complicated). stains pink
Which is more drug sensitive: gram + or gram -?
gram +
gram - is more complex and have a more selective channel giving more drug resistance
What is the peptidoglycan structure?
alternating N-acetyl muramic acid with N-acetyl glucosamine connected via amino acid peptides
How do B-lactam drugs work?
stop cross linking from happening in peptidoglycan so it falls apart
What is found in gram - but not in gram + ?
LPS
What is found in gram + but not in gram - ?
teichoic acids
- woven in peptidoglycan
What is a polysaccharide capsule?
can be in gram +/- and is the outermost surface as another carbohydrate layer
main importance: adhesion to surfaces and cause biofilms, evade immune system, reduce phagocytosis, and shield protein antigens
Where is acid fast staining found and why does it occur?
found in mycobacteria that have gram + walls due to long-chain fatty acid mycelia acid on the exterior
What type of bacteria is E.coli?
gram -
What is the structure of LPS?
lipid A (immuno reactive lipid) and a long carbohydrate called O- antigen
Where are LPS found in gram - bacteria?
outermost layer
What are the polysaccharides of the capsule used as?
vaccines specifically in children
What does HOK stand for?
H- flagella
O- LPS O-antigen
K- capsule
What does HOK stand for?
H- flagella
O- LPS O-antigen
K- capsule
How does the capsule stain?
it doesn’t- it shows up clear on stains
Which bacteria is more common in flagella for motility and fimbriae/pili for attachment?
flagella= both gram + and -
fimbriae/pili= more commonly gram -
How does flagella allow for movement?
they have sensors/receptors on them to detect for specific things/gradients
What is treponema denticole?
oral spirochete that is gram - with a unique flagella in periplasmic space
What is a major virulence factor of E.coli that allows colonization in the urinary tract epithelium?
fimbriae/pili
T/F: Plant cell wall and fungi are the same as bacterial cell walls.
False!
plant/fungi cell walls lack peptidoglycan
