Exam 3: Cell Wall Synthesis

Question 1

Autolysin activity

Answer 1

-cleaves B 1,4 glycosidic linkages between NAG and NAM (to elongate peptidoglycan)
-self lyse in certain places

Question 2

bactoprenol

Answer 2

-facilitates crossover to D-ala
-feed in peptidoglycan precursor to NAG and NAM
-hydrophobic alcohol carrier allows for transport pathway

Question 3

order of NAM linkages

Answer 3

-L-ala
-D-glutamic acid
-DAP
-D-ala
-D-ala

Question 4

Glycosylase Activity

Answer 4

-piece NAG and NAM into cleavage point
-opposite of autolysin
-glycosylase enzyme facilitates linkages (works on sugar component)

Question 5

Transpeptidation

Answer 5

-facilitate crosslinks off NAM (link two peptide chains)
-needs energy, given off by removal of extra D-ala (why we have it)
-facilitated by transpeptidase enzyme (Fts I)

Question 6

Vancomycin antibiotic resistance

Answer 6

binds to D-ala, D-ala but resistance occurs when second D-ala converts into D-lactate

Question 7

Penicillin resistance

Answer 7

changing the conformations in the Fts I

Question 8

vasotracin

Answer 8

topical antibiotic, target bactoprenol