what are the difference between gram positive and negative bacteria?

Question

anonymous · Answer

gram negative bacteria cell wall has 3 layers: outer membrane (this layer has some lipopolysaccharide), peptidoglycan and cytoplamic membrane

gram positive cell wall has 2 layers: peptidoglycan layer with some techoic acid, and cytoplasmic membrane

anonymous · Answer

Excellent answer, @yukitou. Furthermore, the names relate to the appearance of the two groups after the application of a Gram Stain.

Gram positive bacteria appear purple - they "retain" the stain because of their large peptidoglycan layers. Gram negative bacteria appear pink - they do not retain the purple stains due to their low peptidoglycan (but high LPS) cell walls.

kayne · Answer

Hey @james1212, just to supplement what @yukitou and @kma230 have already said, I'd advise you to check out the following videos: http://www.youtube.com/watch?v=NWASSXDzHRs http://www.youtube.com/watch?v=Ly6j4pZFU3A&feature=channel&list=UL I came across these last year just on the eve of my practical test and they really helped me to get a strong grip on gram staining without much effort.