Peptidoglycan Flashcards
1
Q
Importance of PG
A
- provides strength, structure and shape
2
Q
How does PG provide strength?
A
- Resists turgor pressure
- Strong but flexible
3
Q
How does PG provide structure?
A
- anchor for cell wall
4
Q
Composition of PG
A
- Repeating units of NAM and NAG
5
Q
What is NAM?
A
- peptide chain
- connects NAM and NAG
- Beta 1-4 linkage
6
Q
What is NAG? Difference between - and +
A
- Gram - and +
- NEG
—> smaller/tighter packed (7-8nm thick)
—> can have protein bound and be modified w small molecules - POS
–> no charged groups (more spread out - 20-80nm)
–>periplasmic space small
7
Q
Wall teichoic acid
A
- covalently linked NAM or D-alenines of PG
8
Q
Lipoteichoic acid
A
Covalently bound to membrane lipids
9
Q
Stages of PG synthesis
A
- monomer unit of synthesis
- Transferred across membrane
- polymerization of units into glycan chains
- Linking into existing PG
10
Q
What does coordination of synthesis across cytoplasmic membrane accomplish?
A
- shape
- elongation
Division
11
Q
Essential enzymes of synthesis, what do they do?
A
- PBP (a/b)
- form PG
12
Q
Specific proteins in elongation of PG
A
- PBP2 and MreB
13
Q
SPecific proteins in division of PG
A
- PBP2 and FtsZ
14
Q
Fts proteins
A
-Z,A,I,K and Zip
15
Q
What does MreB do?
A
localizes synthsis of PG and allows new cell to form
