Bacterial envelope handout Flashcards
What envelope structures can be found on both Gram+ and Gram- bacteria?
Capsule (slime and glycocalyx) Cell wall (peptidglycan, murein, mucocomplex) Cytoplasmic membrane (inner membrane, cell membrane, plasma membrane)
What is the chemical composition of the capsule?
Polysaccharide gel
What is the function of the capsule structure?
Pathogencity factor protecting against phagocytosis
Immunogenic- **EXCEPT streptococcus pyogens which is hyaluronic acid and non-immunogenic.
What is the chemical composition of the outer membrane structure? And is it Gram+ or Gram-?
Lipopolysaccharide Lipid A
Polysaccharide
Phospholipids
Proteins (porins and outer membrane proteins)
IT IS GRAM-
This protein on top of the gram + cell structure make it stronger?
Peptidoglycan
Only gram +/ - has an outer membrane composed of LPS which is responsible for endotoxic shock?.
gram -
Gram stains work best at what layer?
The peptidoglycan layer
If the stain is violet, what does it mean?
Means it is very small to let in, so put some iodine to allow it to coagulate
- A lab tech forgets the iodine fixation step staining strep. The organism will appear pink/blue/colorless?
Appear pink
With iodine Gram +/- locks in the purple/blue color and is extrememly crosslinked whereas a gram +/- releases the color with iodine?
Gram + locks in the color and gram – releases the color
Endotoxin shock associated with septicemia caused by…?
neisseria meningitides
What is bacterial log phase?
When the cells increase in number by 2’s
What is lag phase?
no growth in cell
What is the generation time?
The time it takes for a bacteria to go from 1 bacterium to 2 daughter cells
What is a stationary phase?;
no increase in the number
nutrients used up -toxic products like acid and alkalis begin to form
Aerobes can/ cannot ferment. Anaerobes are/ are not fermenter.
Aerobes cannot ferment and anaerobes are fermentors.
What are the ABC bacterium?
A-actinomyces,
B-bacteroides,
C- clostridium
Capsules have a ___ layer which allow them to be non-phagocytic?
slime layer
What is ferritin?
Storage form of iron (rmmber ferum in a tin)
List the following from nonbioavalable to most bioavaliable form:
calcim citrate,
calcium glucamate,
calcim carbonate?
Calcium carbonate-calcium citrate-calcium glucamate
LPS (lipopolysacchrides) are the only endotoxins, true/false?
true
Gram + have a mesosome, true/false?
true
Where do gram – have endotoxins?
Outer membrane
Acid fast have what kind of chemical composition?
Mycolic acids : whose function is acid-fsatness and resistence to drying and chemicals.
In Peptidoglycan layer, what two antibiotics inhibit cell wall synthesis?
PCN and cephalosporins
