LECTURE 1- intro to bugs and drugs Flashcards
function of a didid cell wall
resist osmotic lysis and maintain cell shape
who determines shape
intracellular cytoskeletal elements and cell wall
FstZ is similar to what in euks
tubulin
where is FtsZ localized
around the cytokinetic ring
function of FtsZ
division
MreB and ParM euk homolog
actin
localization of MreB
throughout in a spiral-
function of MreB
shape, polarity, and chromosome segregation
CreS homolog in euks
intermediate filamets
localized CreS
along 1 side to curve
CreS function
shape
peptidoglycan is repeating what 2 sugars
N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc)
cross linking of MurNAc in g- is
DAP
cross linking of MurNAc in g+ is
L-Lys
who has more cross linking of polypeptide (g+ or -)
G+
lysoszyme hydrolyzes peptidoglycan by cleaving between what
MurNAc and GlcNAc
thin sparsely cross linked peptidoglycan layer is g+ or g-?
negative
outermsmbrane of gram negative
lipid bilyaer of LPS, lipoproteis, and porosins
functions of g- outer membrane
barrier to antibiotic entry, protects from detergents
where is LPS in g- bacteria
outer leaflet of outer membrane
somatic antigens (aka O antigen) where
outer membrane of G-
g+ peptidoglycan has what else
teichoic acids
what is teichoic acids
repeating polyglycerol P or polyribitol P backbone that can be substituted
purpose of lipoteichoic acids
anchor cell wall to membrane
peritrichous flagella
distributed over suface
clockwise flagella moves how
tumbling
counterclockwise flagella –>
swimming
H antigens are how what gets classified
enteric bacteria on flagella
pili are important for
adherence (unless sex pili- then conjugation)
G- cytoplasmic membrane is where
inner membrane
differece in lipid by layer from bacteria and euks
bacteria have NO sterols and more protein content (60-70%)
6 functions of cytoplasmic membrane
selective permeability, electron transport system, metabolite transport, biosynthesis of lipids and envelope proteins, dan replication, flagellar rotation
what can get through the cytoplasmic membrane win bacteria
uncharbed hydrophobic smaller than glycerol
ribosome in bacteria that does protein syntehsis
70S
R factors
plasmids encoding for resistance
phage conversion
change in phenotype of a host bacterium because a gene from phage gets expressed in host
what phase of growth cycle is bacteria most resistant to antibiotics
stationary
heterotrophic
get carbon from somewhere else
autotrophic
turn CO2 into organic carbon
fastidious
bacteria missing at least 1 biosynthetic pathway so need growth factors
aerobe and example
requires oxygen, cannot ferment, mycobacterium tuberculosis
anaerobe and 2 examples
killed by oxygen, fermentative , clostridium and bacteroides
indifferent define and example
ferments with or without oxygen, streptococcus pyogenes
facultative and 2 examples
respires with O2 and ferments without it, E. coli and staph. aureus
microaerophilic+ ex
grows best at low O2 concentrations and can grow without it, campylobacter jejuni
who produces catalase
things that grow with oxygen
pathogenic anaerobes are most likely
aerotolerant
energy currency
2 forms- ATP for biosynthetic reactions and electrochemical gradients for other functions, convertible via ATPase in membrane
who gives reducing power
NADH and NADPH
heterogrophic bacteria get energy and reducing power via
respiration or fermentation
fermentation who is e donor and acceptor, who does it
organic compounds, NO net oxidation of substrate occurs, anaerobic, facultative, and indifferent
respiration includes what cell organ
mitochondria
how does respiration generate ATp
electron transport with O as final electron acceptor
how does anaerobic respiration work
nitrate or nitrate work as final e acceptor
low levels of what 3 elements–> sporulation
C N aP
how do spores go from spree to cells
germination to become vegetative cells, occurs when in good conditions
b-lactams- what do they target, 2 ex
penicillins, cephalosporins, inhibit final transpeptidation run during peptidoglycan cross linking
vancomycin inhibits what
elongating peptidogylcan change by using lipid-linked intermediates during an intermediate step of peptidoglycan syntehsis
cycloserine inhibits what
alanine racemase so you can’t form a muramyl pentapeptide– intermediate win peptidoglycan synthesis
polymyxins how do they work
cationic surfactants that fuck up outer and cytoplasmic membranes, less active on mammalian cells— TAGETS OUTER AND CYTOPLASMIC MEMBRANE
3 classes of antibiotics that are cell wall active
beta lactams, vancomycin, cycloserine
4 antibiotic classes that inhibit protein synthesis at the ribosomal level
aminoglycosides, tetracyclines, chloramphenicol, macrolides
2 antibiotic classes that inhibit nucleic acid syntehsis
quinolines and rifampicin
4 antibiotic classes that are metabolic inhibitors
sulfonamides, trimethroprim, isoniazid, metronidazole
how do amino glycosides work
bind to target proteins in 30s to inhibit protein syntehsis
6 aminoglycosides
streptomycin, kanamycin, gentamicin, neomycin, tobramycin, amikacin
how do tetracyclines work
reversibly bind 30S and prevent binding of amioacyl tRNA
chloramphenicol how does it work
reversibly binds 50S and precents peptidyl transferase and peptide bond formation
macrolides- 2 exm and how do they work
erythromycin and lincomycins, bind 23S on 50 S to inhibit peptidyl transferase
how do quinolines work
inhibit DNA gyrase and topoisomerase
rifampicin how does it work
inhibits RNA polymerase and fucks with txn initiation
sulfonamides are structural analogs of what
PABA in folic acid
why do bacteria need folic acid derivatives
for 1 carbon transfer reactions in compound synthesis
how do sulfonamides work
compete with folic acid to prevent nuclear acid syntehsis
where do humans get folic acid
from bacteria, we can’t make our own
trimethroprim works how
interferes with folic acid metabolism by inhibiting dihydrofolate reductase, can be toxic to humans!
ionized how does ti work
blocks lipid synthesis in mycobacteria
metronidazole intereferes with
anaerobic metabolism
