cell walls Flashcards
(34 cards)
what makes up the lateral strength of the glycan backbone? (peptidoglycan)
N-acetylglucosamine (NAG)
N-acetylmuric acid (NAM)
how many AA are attached to the tetra peptide?
4 (Ala always attached to NAM)
what bacteria have a glycine inter bridge?
gram-positive
what makes up the horizontal strength in the peptidoglycan?
-tetrapeptides
-glysine interbrige (gram+)
what are optical isomers?
L+D-mirror each other, most carbs are D isomers
what is a peptide cross-link?
distance from attachment of one aa to another (NAM-NAG)
what is DAP?
diaminopimelic acid (only found in cell walls)
what do glycosidic bonds do?
hold together aa
what are proteases?
an enzyme that breaks L-L aa bonds
(resistance to proteases are D+L isomers, DAP
where does synthesis: making the cell wall start?
in the cytoplasm
what seals the glycan backbone?
transglucosidase
what do PBP’s do?
cut off NAG+NAM for cell wall, removes a phosphate group allowing bactoprenol to flip
what is bactoprenol?
C55, made inside the cell, has phosphate groups that are hydrophobic -> allows movement across membrane
what is a park nucleotide?
hydrophilic, NAG+NAM pentapeptide
what forms the cross-link after becoming a tetra peptide?
transpeptidase
what does PBP stand for?
penicillin binding protein
what are the targets in bacterial cell walls?
-NAG+NAM bonds
-transpeptidation
-bactoprenol
what are lysosomes?
protect against gram+ bacteria and infections, produced by saliva tears and all mucous membranes
who discovered lysosomes?
Alexander Flemming
what contain beta-lactams?
penicillins, cephalosporins, carbapenems, monobactams
what are semisynthetic drugs (have been modified in a lab)?
methicillin and amoxicillin
what are B-lactam rings?
a site where enzymes can destroy medications
what does betalactamase do?
chemically modify the drug, breaks the C-N bond on rings destroying the chemical leading to resistance
what medications work against gram+?
natural and semisynthetic penicillins
