Gram Positive & Gram Negative Flashcards
study of the cause; manner of causation of a disease or condition.
Etiology
Who invented Gram Staining?
Hans Christian Gram
A staining technique used to classify bacterial species into large groups
Gram staining or Gram Stain or Gram’s Method
What are the 4 chemical use in Gram Staining?
Crystal violet, Iodine, Ethyl alcohol, Safranin
what is the purpose of Iodine?
Mordant
what is the purpose of ethyl alcohol?
decolorizer
what is the purpose of safranin?
counterstain
what is the purpose of crystal violet?
primary stain
how many second does crystal violet stay?
60 sec
how many second does ethyl alcohol stay?
15 sec
how many second does iodine stay?
60 sec
Describe the characteristics of gram-positive
with inner most plasma membrane
with thick cell wall / peptidoglycan
without a second plasm membrane
with or without an outer capsule
how many second does safranin stay?
60 sec
Describe the characteristics of gram-negative
with inner most plasma membrane
with thin cell wall / peptidoglycan
with a second plasm membrane
with or without an outer capsule
sticky outer layer for protection and attachment
capsule
it is made of peptidoglycan that provides structural support
cell wall
it is a phospholipid bilayer that directs what enters and exits
plasma membrane
a complex glycolipid covering the cell surface of gram-negative bacteria
Lipopolysaccharide
what is the meaning of LPS?
Lipopolysaccharide
what gram has no LPS?
Gram positive
is a virulence factor shielding bacteria from adverse host environments and is sensed by animal as well as plant receptors
Lipopolysaccharide
what gram has LPS?
gram negative
enters the cell of the host
endotoxin
