Question

Give the difference between cell walls of Gram-positive and Gram-negative bacteria.

Answer 1

Gram-positive bacteria	Gram negative bacteria
They remain coloured blue or purple with Gram stain even after washing with absolute alcohol or acetone.	The bacteria do not retain the stain when washed with absolute alcohol.
The wall is single layered. Outer membrane is absent.	The wall is two layered. Outer membrane is present.
The thickness of the wall is 20-80 nm.	It is 8-12 nm.
The lipid content of the wall is quite low.	The lipid content of the wall is 20-30%.
The wall is straight.	The wall is wavy and comes in contact with plasmalemma at a few places.
Murein or mucopeptide is 70-80%.	It is 10-20%.
Porins are absent.	Porins or hydrophilic channels occur in outer membrane of cell wall.
Cell wall contains teichoic acids.	Teichoic acids are absent.