what is the difference between gram-positive bacteria and gram-negative bactria?

Question

what is the difference between gram-positive bacteria and gram-negative bactria?

Answer 1

Gram pos has a thick peptidoglycan layer while gram neg has a thin one.

gram neg has an outer lipopolysaccharide (LPS) layer that gram pos doesn't have.

for the gram stain, you add crystal violet (stain1), iodine (to hold the stain in the bacteria), alcohol(decolourizing agent) and safranin(stain2).

the decolorizing agent degrades the LPS of gram neg and enters the bacteria to decolorize the crystal violet stain. it also dehydrates the peptidoglycan layer of the gram pos bacteria, in a way, sealing the violet dye into the bacteria. after staining with safranin, you should be able to see the difference b/w gram neg and pos bacteria.

Gram pos will be purple, as it has retained stain1 and shut out stain2.
Gram neg will be pink, as it has lost stain1 and took on stain2.

hope this helps!

Answer 2

You are absolutely right. But one thing you must know is that the gram-negative bacteria has a double membrane surrounding each bacterial cell. Although all bacteria have an inner cell membrane, gram-negative bacteria have a unique outer membrane. This outer membrane excludes certain drugs and antibiotics from penetrating the cell, partially accounting for why gram-negative bacteria are generally more resistant to antibiotics than are gram-positive bacteria. There is not any distinction between the Goodness and badness of the bacteria.......any bacteria either gram positive or gram negative may be good or bad. Was my answer helpful??

Answer 3

The Gram stain is a method for staining bacteria using a red dye, alcohol and a blue dye.

When you want to look at bacteria you take a little bit of bacteria mixed with water and smear it on a slide. Then you let it dry. You put blue dye on it. Then after a minute you wash off the blue dye with alcohol. Some bacteria will hold the dye and it will not be washed off. Other bacteria will be stained blue, but the alcohol will wash off the blue and the bacteria will be colorless. Then you put on red dye. The bacteria that were colorless will take up the red dye. When you look at the slide under the microscope the different bacteria appear blue (gram positive) or red (gram negative).

This happens because the outside walls of the bacteria are different between the two types. This makes a big difference because a lot of antibiotics attack the bacteria at their cell walls. You need a different kind of antibiotic to attack the gram positive bacteria than you use for the gram negative. Identifying whether it is gram + or gram - helps the physician to decide what drug to use in treating the infection, and also help identify which bacterial it is, so that he can understand how the disease is likely to develop.