microbiology Flashcards
name the groups of microorganisms
fungi protozoa bacteria virus prions
what are protozoa
unicellular eukaryotes
free living in enviroments
forms of fungi
saprophytes
parasites
commensals
life cycles of fungi
mould and yeast
spores
hyphae
what do fungi have
external rigid cell walls 0
(chitin and polysaccharides
what are bacteria
prokaryotes
no internal membranous compartments
what do bacteria produced
range of toxins
classifications of bacteria
cellular form
cell wall structure
shapes of bacteria
bacilli extended irregular rods kidney bean corkscrew helical
sizes of bacteria
cocci - single dipolococci - 2 tetrads - 4 sarcina - many cube streptococci - line staphylococci - grape
2 types of cell wall
gram positive
gram negative
describe gram positve
one membrane
thick peptidoglycan layer
thicker wall than -
purple under stain
describe gram negative
two cell membranes periplasm (space between membranes) outer capsule of LPS pink stained outer membrane has transport proteins)
lab cultivation to grow bacteria
bunsen burner for sterilisation
grow in rich media
stain and drug test bacteria
stages of bacterial growth
lag - adjustment period
log - fast growth
stationary - lack of growth e.g. lack of food
how does exponential growth occur
A sexual reproduction
how can genetic transfer occur
conjugation
transformation
transposons
horizontal gene transfer
how does conjugation occur
transfer of DNA down sex pilus
transformation
natural uptake from environment
transposons
jumping gnes
horizontal gene transfer
genes swapped between bacteria and within populationsn
types of bacterial metabolism
autotrophs
heterotrophs
where can heterotrophs get their food from
carbon source
nitrogen source
terminal electron acceptor
what are pathogens
disease causing bacteria
what are opportunistic pathogens
commensals that can sometimes cause disease
what are commensals
unseen hordes which live harmlessly
how do bacteria move
via flagella or pili
what can bacteria use for environmental sruvivial
endospores
structure of viruses
nucleic acid in proteinaceous capsid
proteins on surface
lipid coat
virus which attack bacteria only
bacteriophage
what is the lytic life cycle
virus binds and uncoats
protein shared
enzymes in genome of cell makes new virus particles
released or remains in the cell
what is viral latency
infection without lytic life cycle
what is latent infection
virus hides in nerve ganglion
when rundown
symptoms can occur
what do latent infections do
incorporate into genome or
reside in cells in active state
what is a prion
protein that causes disease
how do prions work
normal PrPc covered to rogue PrPSC
aggregate into long fibres in brain
affects proteins involved with neurotransmission
describe candida (fungo) in the mouth
white patches which grow on throat
candida cells firkin and epithelial cells
