What is the differences between gram positive and gram negative cells?

Answer 1

Gram was a scientist who invented a technique called Gram staining by which bacteria can be colorized and divided into two groups.

Gram positive

appearance: blue to transfer to purple

Structure: Have thick layer of peptidoglycan over inner cytoplasmic membrane.

They lack LPS-lipopolysaccharides.

Gram negative

appearance: pink to transfer to red

Structure: In gram negative bacteria the peptidoglycan layer is thinner and is located between space of the outer and inner cytoplasmic membrane.

The cell wall contains LPS, which make them virulent.

Answer 2

Gram positive cells have a thick peptidoglycan layer and no outer membrane, while gram negative cells have a thin peptidoglycan layer sandwiched between an outer and inner membrane. Gram positive cells appear purple after staining, while gram negative cells appear pink. Gram negative cells are generally more resistant to antibiotics due to the presence of the outer membrane.

Answer 3

gram positive and negative are differentiated on the basis of the difference in their cell wall which gives different staining color on staining

The gram stain was developed by German scientis Gram he stain the baceteria with crystal violet and counter stain with saffranine

The bacteria which gives blue colour are gram positive and have thick cell wall

and those which give pink or red colour are gram negative and have thin but many layer cell wall

Answer 4

there is only difference in gram positive and negative is of cell wall as :

The Gram positive cell wall

The Gram positive cell wall is characterised by the presence of a very thick peptidoglycan layer, which is responsible for the retention of the crystal violet dyes during the Gram staining procedure. It is found exclusively in organisms belonging to the Actinobacteria (or high %G+C Gram positive organisms) and the Firmicutes (or low %G+C Gram positive organisms). Bacteria within the Deinococcus-Thermus group may also exhibit Gram positive staining behaviour but contain some cell wall structures typical of Gram negative organisms. Imbedded in the Gram positive cell wall are polyalcohols called teichoic acids, some of which are lipid-linked to form lipoteichoic acids. Because lipoteichoic acids are covalently linked to lipids within the cytoplasmic membrane they are responsible for linking the peptidoglycan to the cytoplasmic membrane. Teichoic acids give the Gram positive cell wall an overall negative charge due to the presence of phosphodiester bonds between teichoic acid monomers.

The Gram negative cell wall

Unlike the Gram positive cell wall, the Gram negative cell wall contains a thin peptidoglycan layer adjacent to the cytoplasmic membrane, which is responsible for the cell wall's inability to retain the crystal violet stain upon decolourisation with ethanol during Gram staining. In addition to the peptidoglycan layer the Gram negative cell wall also contains an additional outer membrane composed by phospholipids and lipopolysaccharides which face into the external environment. The highly charged nature of lipopolysaccharides confer an overall negative charge to the Gram negative cell wall. The chemical structure of the outer membrane lipopolysaccharides is often unique to specific bacterial strains (i.e. sub-species) and is responsible for many of the antigenic properties of these strains.

As a phospholipid bilayer, the lipid portion of the outer membrane is largely impermeable to all charged molecules. However, channels called porins are present in the outer membrane that allow for passive transport of many ions, sugars and amino acids across the outer membrane. These molecules are therefore present in the periplasm, the region between the plasma membrane and outer membrane. The periplasm contains the peptidoglycan layer and many proteins responsible for substrate binding or hydrolysis and reception of extracellular signals. The periplasm is thought to exist as a gel-like state rather than a liquid due to the high concentration of proteins and peptidoglycan found within it. Because of its location between the cytoplasmic and outer membranes, signals received and substrates bound are available to be transported across the cytoplasmic membrane using transport and signalling proteins imbedded there.

Answer 5

Although their cell walls are similar in chemical composition, the cell wall of a gram-negative bacteria is a thin layer sandwiched between an outer lipid-containing cell envelope and the inner cell membrane. The gram-positive bacteria cell wall is much thicker and has no inner membrane. This thicker cell wall contains additional substances such as teichoic acids. Gram-positive bacteria are generally more sensitive to growth inhibition by dyes, halogens, many antibiotics, and to attack by phagocytosis, and they are more resistant to digestion by the enzymes pepsin and trypsin and the enzymes in animal sera. Typical gram-positive bacteria are those staphylococci that produce boils; typical gram-negative bacteria are the bacilli that cause whooping cough. Bacteria that may or may not retain the blue color of Gram's Stain are known as gram-variable; typical gram-variable bacteria are the bacilli that cause tuberculosis.

Answer 6

The main difference between gram positive and gram negative bacteria is the components of the cell wall.

In gram positive bacteria, the cell membrane is surrounded by multiple peptidoglycan layers that have teichoic acids woven through and then an S-layer and then a layer of glycosyl chains.

Gram negative bacteria on the other hand have an inner membrane, then a much smaller layer of peptidoglycan called the periplasm which is surrounded by an outer membrane.

Answer 7

Merely the difference in peptidoglycan cell wall construction. Gram positive bacteria have one thick cell wall that easily holds the stain and shows the proper color. Gram negative bacteria have thinner peptidoglycan cell walls and theu are two layers thick with a gap between them. Does not hold the stain.

Answer 8

The difference between gram negative and gram positive bacteria is the structure of their cell walls. The gram negative bacteria cell wall is a thin peptidoglycan layer and an outer cell membrane with a lipopolysaccharide layer. The gram positive bacteria cell wall is a single thick peptidoglycan layer. This wall forms in a mesh like formation of three layers of alternating material.

Answer 9

Gram positive bacteria have one thick cell wall made of peptidoglycan that easily holds the Gram stain after being washed. Gram negative bacteria have two thinner cell walls of peptidoglycan that allows the Gram stain to be washed away and not show under light.

Answer 10

Gram-positive bacteria have thick peptidoglycan walls, and typically lack an outer membrane.

Gram-negative bacteria lack thick peptidoglycan walls, and have an outer membrane.