Bacterial structure Flashcards
lag phase
no increase in cell number due to adaptation
log (exponential phase)
active and uniform growth
Stationary phase
growth and death balance because food runs out which makes peptides signal to stop growing
Death phase
cells die rapidly
clinical significance of stationary phase?
stationary phase cells are resistant to some cell wall antibiotics
what are the nutritional requirements for heterotrophic bacteria?
requires organic matter like glucose, carbon source, and oxidative phosphorylation
minimal defined and undefined media is for ?
clinic (diagnosis) and research
what is glycocalyx?
capsules and biofilms
capsules used for antiphagocytosis
biofilms and slime used for immune surveillance and antibiotic resistance by preventing it from penetrating
what are important virulent factors?
capsules
what are nucleoids?
(in prokaryotes where all genetic material is contained)
double stranded circular DNA molecule
not bounded by membranes
bacterial chromosomes are condensed into supercoiled loop domains
what are plasmids?
autonomously replicating circular DNA
antibiotic resistance, produces toxins
takes effect by bacterial conjugation
what are ribosomes?
synthesizes proteins
are large, 80 protein - RNA complexes
prokaryotic ribosomes are smaller than eukaryotic ribosomes and are sensitive to antibiotics that do not affect eukaryotic ribosomes
which factors influence bacterial growth?
pH- (acidophiles, neutrophiles, or alkaliphiles)
atmosphere- (anaerobes, aerobes, or facultative anaerobes)
Temperature - (flora of human body)
Osmolarity - (halophilic - high [salt] or osmophilic- high osmotic pressure)
what is the growth rate of TB?
what is the growth rate of pseudomonas?
TB is slow growing 12 hours doubling time
Pseudomonas is fast growing 20 min doubling time
why is it good to be a non-enveloped virus?
because No drying! resistant to drying
