Bacterial cell wall = peptidoglycan layer?

[regeneration]

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Does the cell wall in bacteria refer to only the peptidoglycan layer? Or does it also include the cell membrane that's found in gram positive and gram negative bacteria? And does it also include the 'outer membrane' found in gram negative bacteria? Can't seem to find a concrete answer.

Thanks.

 

[ouroboros39]

According to the Campbell textbook, The "Cell wall" of Gram positive bacteria is just the Peptidoglycan layer, but for Gram negative, it is the Peptidoglycan Layer + the Outer Lipid Bi-layer.

It does not show this or explicitly state it, but I assume that the cell wall does not include the capsule/slime layer that is found on the very outside.

They also mention that the outer bi-lipid layer in Gram negative bacteria is actually

"an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids)."

So I guess that means that its fundamental unit is the lipopolysaccharide as opposed to the phospholipid bilayer of the inner membrane - Im just basing this off the assumption that the plasma membranes of bacteria and eukarya are supposed to be similar.

 

[deleted92121]

Gram Positive = Peptidoglycan dominant cell wall which is the outermost covering

Gram Negative = Less peptidoglycan, more complex cell wall that is between the plasma membrane and an outer membrane

 

[chem4ever]

According to the Campbell textbook, The "Cell wall" of Gram positive bacteria is just the Peptidoglycan layer, but for Gram negative, it is the Peptidoglycan Layer + the Outer Lipid Bi-layer.

It does not show this or explicitly state it, but I assume that the cell wall does not include the capsule/slime layer that is found on the very outside.

They also mention that the outer bi-lipid layer in Gram negative bacteria is actually

"an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids)."

So I guess that means that its fundamental unit is the lipopolysaccharide as opposed to the phospholipid bilayer of the inner membrane - Im just basing this off the assumption that the plasma membranes of bacteria and eukarya are supposed to be similar.

No, it's a regular phospholipid bilayer....the lipopolysaccharides anchor the outer phospholipid bilayer the peptidoglycan layer. See EK Lecture 3 for a great picture of this.

 

[ouroboros39]

Yeah, that makes sense - I guess I took the book saying "contains" lipopolysacharides to mean was "composed of" lol - Thanks.