Structure Unique To Bacteria Flashcards
What is the cell wall of bacteria made from
Peptidoglycans (glycan polymers)
Muramic acid and n acetyl glucosamine linked with peptide cross bridges via transpeptidase
Name 3 ways peptidoglycan cell wall is important
1- target from antibiotics like penecillin
2- keeps osmotic pressure stable
3- protection from cell lysis (which happens due to b lactam)
Explain the gram +ve cell wall
They have large peptidoglycan wall over their single layer membrane
What are the anionic polymers called in the cell walls of gram +ve
Teichoic acids
What are teichoic acids important for in gram +ve
Needed for bacteria survival
Also are antigenic so produce an immune response
How is the cell wall different in gram negative
They have a thin peptidoglycan cell wall embedded between a double cell membrane
What is the structure in gram negative which contains both the peptidoglycan cell wall and inner membrane
Periplasm
What is found on the outer membrane of gram negative
Lipopolysaccharide layer with lipid A and polysaccharides
What is lipid A on the outer membrane for in gram negative
It produces pyrogenic toxins which cause a fever in infected cells
How is the lipopolysaccharide layer important in gram negative defence mechanism
They can shed and add a new one which is unrecognised by our immune system
What is a crystalline protein lattice called on the outer layer of all bacteria and archaea
Proteinaceous s layer
What is the proteinaceous s layer for
It acts as a selective sieve for protection
What is the capsule made of and how is it attached to the cell wall
It’s a polysaccharide which is covalently attached to the cell wall peptidoglycan
Why is the capsule important to bacteria
It helps defend immune system in phagocytosis
Is the capsule immunogenic (forms immune response like teichoic acids)
Yes sometimes it is
