Why are some bacteria gram-positive and some gram-negative?

Answer 1

During a gram stain some bacteria retains the stain because they are gram positive with thicker walls . If the bacteria does not stain either it is an endospore bacteria or gram negative with thinner walls, so colorless or red color.

Answer 2

Biologist group most species of bacteria into two categories based on structures of their cell walls. Gram-negative bacteria have cells walls that are complex and and have small amount of peptidoglycan. Gram-negative bacteria take up the second, red dye of the Gram stain process which makes the cells appear reddish pink. Gram-positive bacteria are simpler and have much more peptidoglycan which retains the purple in their cell walls and appear purple.

Answer 3

Some bacteria test Gram positive because they have a thick cell wall made up of peptidoglycan that traps the crystal violet in the cytoplasm. Others test Gram negative because they have a thinner layer of peptidoglycan and crystal violet is easily rinsed from the cytoplasm.

Answer 4

Gram-positive bacteria have a cell wall consisting of a plasma membrane, periplasmic space, and a peptidoglycan layer.

Gram-negative bacteria have the same cell wall structures as gram-positive bacteria. However, they have an additional periplasmic space and outer membrane made of lipopolysaccharide and protein.

Answer 5

Gram-positive bacteria have a thick peptidoglycan layer in their cell wall that retains the crystal violet stain used in Gram staining, giving them a purple color. Gram-negative bacteria have an outer membrane that makes their peptidoglycan layer thin and unable to retain the stain, causing them to appear pink or red. This structural difference is due to the composition of their cell walls.