Chapter 8

Question 1

what are features of peptidoglycan biosynthesis?

Answer 1

1. In cocci, cell walls only grow in
   opposite directions outward from the
   FtsZ ring
2. Preexisting peptidoglycan needs to be
   severed to allow newly synthesized
   peptidoglycan to form
3. All bacterial cells must synthesize new
   peptidoglycan and export it outside
   the cytoplasmic membrane

Question 2

what molecule is responsible for carrying peptidoglycan precursors through the cytoplasmic membrane?

Answer 2

bactoprenol (highly hydrophobic)

Question 3

what is lipid II?
what does it consist of?

Answer 3

the entire molecule including bactoprenol bound to the peptidoglycan precursor
consists of N-acetylglucosamine (G), N-acetylmuramic acid (M), and a
pentapeptide

Question 4

describe the steps of biofilm formation

Answer 4

1. Random collision leads to initial
   attachment, facilitated by structures
   like flagella or by cell surface proteins
2. Attachment causes expression of
   biofilm-specific genes encoding
   proteins for intercellular
   communication and extracellular
   polysaccharides
3. Cyclic di-GMP is used as an intracellular
   signaling molecule. Accumulation
   triggers a transition from planktonic to
   biofilm growth

Question 5

how are GTP used in biofilm formation and what are the effects of it?

Answer 5

1. they get converted into c-di-GMP by proteins with the GCDEF domain
2. phosphodiesterases degarde c-di-GMP

effects: modifications to extracellular polysaccharides and proteins, reduced motility and virulence

Question 6

what is Pseudomonas aeruginosa?

Answer 6

an oppurtunistic pathogen that forms a tenacious biofilm containing polysaccharides that increase pathogenicity and prevent antibiotic prevention