Download The Gram Stain Can you say Peptidoglycan?

The Gram Stain
Can you say
Peptidoglycan?
Friggin ice ant
get the hell out of my way
But first,
a brief yet tasty guitar
riff by Chris Impelliteri
1
I. Bacterial Cell Surface
A. The majority have cell walls
1. structure that immediately surrounds the
plasma membrane
2. maintains cell shape, protecting the cell
in both hypotonic and hypertonic
environments
3. contains peptidoglycan - a modified
sugar polymer cross linked by short
polypeptides
a. found only in prokaryotes
II. The Gram Stain
[0nly effective on 24 hr. cultures]
A. Used to differentiate bacteria into two groups
B. Gram Positive bacteria
1. simple cell walls with a thick peptidoglycan
layer
2. stain blue when using Gram stain protocol
C. Gram Negative bacteria - stains pink
1. more complex cell walls w/smaller amounts of
peptidiglycan
2. more likely to be pathogenic
3. lipopolysaccharide layer covering the cell wall
(often toxic, protecting the cell from drugs and
host immune system)
2
Cell Wall: Gram (+) v. Gram (-)
pg. 529
The End
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