Micro exam 1 Flashcards
Mycoplasma
smallest, simplest organism
Taxonomy is based on (2)
morphological and molecular relatedness
Organism are named by
Genus (italic and capitalized) and species ( only italicized)
Three groups of taxonomy
classification, nomenclature, and identification
Taxonomy order acronym:
Dear King Philip Came Over For Good Soup
Domain Kingdome Phylum Class Order Family Genus Species
Cell Wall compositions for each domain
Bacteria: Murein with muramic acid
Archaea: no muramic acid
Eukar: no muramic acid
Sequence alighnemnt
adds gaps to establish positional homology – line up nucleotides match between different organisms adds gap where needed to better fit
bootstrapping
can deal with uncertainty; indicates percentage of time a node is supported by data
homoplasy
(convergent evolution) complicates tree construction when similar sequence positions result from recurrent mutation instead of inheritance
coccus
sphere
bacillus
rod or cylinder
coccobacillus
short round rod
vibrio
curved rod
spriillum
more rigid spiral shape
spirochete
more flexible spiral shape (flagella between out membrane and peptidoglycan layer)
mycelium
network of long multicellular filaments
pleomorphic
organisms that are variable i shape
diplococci
pairs
streptococci
chains
plasma membrane free flows:
O2, CO2, N2
plasms membrane blocked from free passage
large, charged molecules, H+, sugar, amino acids
peripheral protein
only on inner membrane
integral proteins
goes all the way through the membrane - not easily removed
Bacteria have no sterols– instead they have
hopanoids
amphipathic and amphiphilic
both hydrophilic and phobic
archaeal membranes
monolayer; lipid branched chain, connected to glycerol by ether linkage not ester linkage
In the prokaryotic cytoskeleton
FtsZ, MreB, crescentin
FtsZ
equal to tubulin - for cell division, circular filament, scaffolding; septation Zring formation
inclusion bodies
granules of organic or inorganic material that are stockpiled
cyanophycin granules
large polypeptides about equal quantites of arginine and aspartic acid
carboxysomes
contain enzyme ribulose-1,5 bisphosphate carboxylase (rubisco) for CO2 fixation
gas vaculoles
found in cyanobacteria (aquatic), buoyancy, gas vesicles, permeable to gasses not water
magnetosomes
iron oxide or iron sulfate in organelle, cytoskeletal, magnetic sensing
Archaea cell walls
no peptidoglycan but have pseudopeptidoglycan instead
some bacterial have no cell walls such as
mycoplasma; sterols in membrane
primary stain
crystal violet
mordant
gram iodine
decolorizer
alcohol
secondary stain/counter
safranin
gram positive results
violet: peptidoglycan layer (murein)
gram negative -
peptidoglycan layer with outer membrane
periplasmic
space between membrane and cell wall and plasma and out membrane
peptidoglycan
contain N-acetyl glucosamine and N Acetylmuramic acid and several different amino acids - D-Glutamic acid - D alanine, DAP
Lipopolysaccharides (LPS) made of
Lipid A, Core polysaccharide, O side chain
LPS
protect form host defenses and environment, attach to surface, exotoxin
Layers of material outside to cell walls
capsule, slime layers
Capsules are
hard to remove
slime layers are
easy to remove
S-layers
layers of protein or glycoprotein, external to cell wall
flagella
extends to exterior; motile throug sensing chemotaxis
hook
connect filament to cell
basal body
anchors flagellum into cell wall
pili
similar called fimbriae
sec-dependent protein secretion
translocates proteins from cytoplasm across; or into plasma membrane
autotroph
use co2 as sole carbon source must obtain other energy
heterotrophs
use organic molecules as of organic or inorganic compounds
phototrophs
energy from light
chemotrophs
energy from oxidation of organic or inorganic compounds
lithotrophs
electrons from reduced inorganic molecules
organotrophs
electrons from organic molecule **diatoms require silicic acid
Nitrogen
N supplied in many ways ammonia, nitrate, nitrogen gas (fixation)
P supplied as
inorganic P
sulfur supplied through
assimilatory sulfate reduction
sugar phosphotransferase system
sugar phophorylated using phsophoenolpyhruvate
phosphoenolpyruvate
phosphate donor
iron uptake
ferric iron is insoluble: use siderophores to uptake; take Fe3+ and transported to cell
Growth factors needed:
-amino acids
-purine and pyrimidines
-vitamins - enzyme cofactors
Environmental factors affecting growth
Temperature
Increase in cell number
Increase in cell size
Psychrophile
(-15-15) degrees celcius
Psychrotroph
(20-30) degrees celcius
Mesophile
(25-45) degrees celecius
Thermophiles
(45-70) degrees celecius
hyperthermophiles
(70-110) degrees celecius
increase in cell size
coenocytic eukaryotes
prokaryote cell cycle (2 parts)
DNA replication and partition
cytokinesis
Parts of circular chromosome
Origin
Terminus
Replisome
MreB
Lag phase
replenishing spent materials, adapting to new medium or conditions
Exponential growth binary fission equation
Nt= N0 x 2^n
n= (logNt - logN0) / log2
Exponential phase
log phase
rate growth is constant
Balanced growth
during log phase exhibited
Unbalanced growth
cell components vary
change in nutrients
change in environment
change in nutrients
shift up - poor to rich food
shift down - rich to poor food
stationary phase
total number of viable cells remain constant
metabolically active cells stop reproducing OR reproductive rate = death rate
Why might it enter this stationary phase
nutrients limits
limited oxygen
toxic waste
critical population density reached
Death phase
alive but dormant
fraction of population suicide program
