Cell membranes and Cell Walls of Prokaryotes Flashcards
(5 cards)
What is the difference between bacterial vs archaeal cell walls?
what material does one lack?
Archaea lack peptidoglycan but have cell walls made of different polysarccharides as well as pseudopetidoglycan that contain N-acteyltalosaminuronic acid linked by Beta - 1,3 bonds.
Bacteria have peptidoglycan with N-acetylmuramic acid linked by B-1,4
Bacterial cell walls
What is the difference between gram-negative and -positive cell walls?
what are the basic structures/order included?
Gram-negative: membrane, periplasm w/ peptidoglycan, outer membrane
Gram-positive: membrane, peptidoglycan
inner membrane in between is not considered the cell wall
- the list provided is in order of the layer from inside to outside
- for gram-negative the periplasm has a thin layer (gram positive has a thicker layer) of peptidoglycan in the middle
Bacterial cell wall
What are molecules that included in the cell wall of gram positive cells? How do they interact with it?
This is within the petidoglycan region (it)
Teichoic acid - polyglycerol; anchored
Lipiteichoic acid - hydrophobic portion helps anchor them into the cytoplasmic cell membrane
Bacterial cell wall
What are molecules that included in the cell wall of gram negative cells? what are their use?
This is within the outermembrane
Porins - tranversive membranes that allow for small molecules to enter the perisplamic space
Lipopolysaccharide - usually for typing bacterial strands based on the different sugars
Lipopolysaccharides have lipids embedded into the outer cell membrane and the sugars (core polysaccharide and O-specific polysaccharide) are sticking out at the top
What are teichoic acid and lipoteichoic acids made up of?
What are their subunits?
Teichoic acids - composed of repeating sunits of ribotol phosphate or glycerol phsophate
lipoteichoic acids - are teichoic acids that are covalently bound to phsopholipids in the cellular membrane
- these acids are found in gram-positive cell walls
