Cell Systems Flashcards
bacteria characteristic of microbial life
defined structure
metabolism
growth and reproduction
response to stimulus
Much variability of life adaptation is expected
among ___as compared to plants and
animals
bacteria
variations at the cell level means ____ to specific chemical or physical environments
adaptation
Many bacteria have similar cellular morphology but differ in
that they have specific ____characteristics that reflect
physiological adaptations.
biochemical
- With Average length of 0.1–0.5 µm
nanobacteria
common characteristic of nano bacteria
host dependent
lack cell wall or obligate parasites
found in soil, freshwater, and marine environments with nutrient limiting environments
deficient in some genes preventing them from growing
outside hosts
what common characteristics of nano bacteria
host dependent
example of nanobacteria host dependent
Buchnera aphidicola
Found in soil, freshwater and marine environments with nutrient- limiting
environments
what bacteria
nanobacteria
a symbiont of insects lacking many genes that cannot grow outside the host
buchnera
are specialized cells in insects that house symbiotic bacteria and fungi
bacteriocytes
Cells with a high surface-to-volume ratio would more rapidly distribute
chemicals within the cell than cells with a lower surface- to-volume ratio.
large prokaryotes
large microorganisms have adjusted to counter the low surface-to- volume
ratio by having active cytoplasmic metabolism primarily adjacent to the
plasma membrane.
large prokaryotes
large prokaryotes have adjusted to counter the low surface to volume ratio by having
active cytoplasmic metabolism adjacent to plasma membrane
largest bacterium
Thiomargarita magnifica
It is the movement of an
organism or entity in response
to a chemical stimulus
chemotaxis
- It is a mechanism by which
bacteria efficiently and rapidly
respond to changes in the
chemical composition of their
environment, approaching
chemically favorable
environments and avoiding
unfavorable ones
chemotaxis
is the movement of an organism toward a higher concentration of a chemical stimulus
positive chemotaxis
is when cells move away from a chemical signal, toward areas with a lower concentration of that chemical.
negative chemotaxis
It is a motile organelle
composed of thousands of
protein subunits.
bacterial flagellum
in eukaryotic bacteria, their flagellum is made up of
microtubule
The filamentous part that
extends from the cell membrane
is called the ___ ____ and
consists of three major parts
axial structure
three major parts of bacterial flagellum
filament
hook
basal body
- made of globular
protein flagellin in chains to
form a hollow core
filament
end of the filament.
hook
anchors
flagellum to cell wall and
plasma membrane through
series of rings
basal body
– aligns the flagella into a single rotating bundle, causing the bacterium
to swim in a straight line.
counter clockwise rotation
breaks the flagella bundle apart such that each flagellum points in a different
direction, causing the bacterium to tumble in place
clockwise rotation
These are bundles of
flagella called
axial filaments
These are bundles of
flagella called axial filaments
that wrap around the cell
body of spirochetes.
endoflagella
- The axial filaments cause
the bundles of flagella to
rotate to help the ___
move in a twisting motion.
spirochete
gram reaction of spirochete
gram negative
- Is the ability of certain rodshaped bacteria to translocate
on surfaces without the aid of
external appendages such as
flagella, cilia, or pili.
gliding motility
This motility is crucial to their
developmental cycle because
it regulates their proliferation in
the presence of nutrients or
aggregation to form fruiting
bodies in starvation conditions
gliding motility
example of bacteria that employs gliding motility
Flavobacterium johnsoniae
- It cause cells of magnetotactic
bacteria to passively align and
swim along the Earth’s magnetic
field lines, as miniature motile
compass needles.
magnetostomes
magnetostomes are found in what kind of bacteria
chemolitotrophic
These are specialized
compartments consist of a
phospholipid bilayer membrane
surrounding magnetic crystals of
magnetite (Fe3O4
) or greigite
(Fe3S4
magnetostomesm
magnetite
Fe3O4
geigite
Fe3S4
s a hollow
structure made of protein, it
usually has the form of a
cylindrical tube closed by
conical end caps.
gas vesicle
utilized by aquatic microorganisms for buoyancy eg. cyanobacteria
gas vesicles
- Gas vesicles occur in ___
phyla of the Bacteria and ___
groups of the Archaea, but
they are mostly restricted to
___microorganisms,
in which they provide
buoyancy
5
2
planktonic
random walk motion is attributed to the rotation of ___ driven by proton reentry at the plasma membrane-flagellum interface
flagella
flagella at the ends of rigid spirochetes is located between envelope and cell wall; enables cell to move in viscous matrix
endoflagella
“corkscrew” action
endoflagella
encapsulated bacteria slide across a surface byt an unknown mechanism
gliding (cell surface)
an aggregate of Fe3O4 that is found by a small granule and frequently occurs as a chain of granules in a cell
magnetostomes
cytoplasm of aquatic bacteria have intracellujlar cylinder-like structures filled with gas and regulate cell buoyancy
gas vacuoles
structures that microbes use to protect
themselves
endospores
- It is a drastic response
undertaken by some
bacteria (mostly Firmicutes)
in response to extreme
stress.
sporulation
During sporulation, the
growing cell (also referred to
as a vegetative cell) will
forego normal cellular
division to instead form an
___.
endospore
anaerobic, when O2 is available they are inside of their
endospore
clostridium tetani
happens when
favorable conditions exists
vegetative cell formation
sporulation mechanism (6)
end of vegetative stage
asymmetric cell division
engulfment
forming cortex
forming spore coat
maturation and mother cell lysis
It is an enveloped, thick-walled,
non-motile, dormant cell formed
by filamentous, heterocystforming cyanobacteria under the
order Nostocales and
Stigonematales
akinete
akinete is unique for
cyanobacteria
resistant structures that are resistant to cold
and desiccatio
akinete
Is a type of asexual reproductive
spore of fungi usually produced
at the tip or side of hyphae or on
special spore-producing
structures called conidiophores
conidia
conidia Is a type of asexual reproductive
spore of fungi usually produced
at the tip or side of hyphae or on
special spore-producing
structures called ____
conidiophore
The main function of the conidia
is to
germinate and create a new generation
- These spores also have a very
important role to play in biological
dispersal
conidia
two morphological stage of a cyst forming microorganism
cyst
trophozoite
s a single-celled organism that is the active feeding stage of certain protozoa
trophozoite
- It is a resting or dormant stage of a microorganism, usually a
bacterium or a protist, that helps the organism to survive in
unfavorable environmental conditions.
cyst
These are diverse
intracellular non-living
substances that are not
bound by membranes.
cell inclusions
cell inclusions include
stored nutrient substances
secretory products
pigment granules
inclusion for buoyancy in vertical water column
gas vesicles
site of CO2 fixation, enzymes for autotrophic CO2 fixation
carboxysomes
reserve carbon and energy phoasphates, linear polymers of PO4
metachromatic granules
reserve C and energy source, polyglucose
glycogen bodies
bacterial organelles that store excess carbohydrates in the form of water-insoluble polyhydroxybutyrate (PHB)
pHB granules
reserve C source, made of amylose and amylopectin
starch granules
orienting and migrating along geomagnetic field lines, made up of magnetite, iron oxide, Fe3O4
magnetostomes
reserve of electrons in phototrophs and reserve of energy source in lithotrophs, made of elemental sulfur
sulfur granules
light harvesting pigments and antennae, made of bacteriochlorophyll, proteins, and lipids
chlorosomes
Biofilms and microbial aggregates are a common mechanism
for the ___of bacteria in nature.
survival
S are communities of microorganisms
attached to a living or inert surface in an aqueous
environment and surrounded in a matrix of extracellular
polymeric substances
microbial biofilms
- bacteria of the same type form
multicellular clumps that eventually settle at the bottom of
culture tubes
autoaggregation
is a process
by which genetically distinct
bacteria become attached to one
another via specific molecules,
such adhesion influences the
development of complex multispecies biofilms
coaggregation
this lead to oral diseaes such as dental caries and periodental disease
dental plaque (biofilm)
are those whose cells are not
separated following cell
division and so tend to grow in
the form of ‘FILAMENTS
filaments
Microorganisms with filamentous
growthmay have a ___
advantage overindividual cells
nutritional
structure of fungal cells that used to grow and gather nutrients
hypha
fungi associated with plant roots
mycorrhiza
System within the microbes body used to react on stimulus/external
factors.
sensory system
- Bacteria have a well-developed sensory system that allows them to
swim toward ____, which are usually nutrients, and away from
____
attractants
repellents
collective behaviors include (3)
bioluminescence
antibiotic production
conjugation
biofilm formation
virulence factors
These systems typically involve a single protein that can sense an environmental signal and directly affect a cellular response
one component transduction system
These systems involve two main components: a sensor histidine kinase (HK) and a response regulator (RR)
two component signal transduction system
often found in eukaryotes, such as the MAP kinase pathways
one component transduction system
system where stimulus is chemical attracts or repel swimming bacteria
chemotaxis
system where stimulus is high cell density or increased pH or temperature
spore production
system where stimulus is chemical secreted by plant roots
rhizobial symbiosis
system where stimulus is increased osmotic pressure
porin production
system where stimulus is presence of metals at sublethal concentration
resistance to heavy metals
system where stimulus is changes in pH, temperature, or osmotic pressure
toxin production
system where stimulus is deficiency of chemicals for metabolism in environment
production of extracellular protease or amlyase
system where stimulus is influenced by nitrate or ammonium present
assimilation of nitrogen
system where stimulus is increase in osmotic state
capsule synthesis
system where stimulus is oxygen concentration in the environment
redox response in heterotrophs
It is the regulation of gene expression in response to
fluctuations in cell-population density.
quorum sensing
Quorum sensing bacteria produce and release chemical
signal molecules called a
autoinducers
ncrease in
concentration as a function of cell density
autoinducers
It is a cluster of genes that are transcribed together to give a
single messenger RNA (mRNA) molecule, which therefore
encodes multiple proteins
operon
where repressor and
activator attaches
repressor gene
s a group of genes that control the metabolism of lactose in bacteria
lac operon
hydrolyse lactose into glucose and galactose
B-galactosidase
lactose transporter into cell
permease
adds acetly group to galactose
transacetylase
It is a collection of genes or operons that respond to a
specific signal by a single regulatory protein by turning on or
off
regulon
refers to a set of regulons capable of producing
changes in response to stress. Since this involves several
regulons, several regulatory mechanisms are employed in the
regulation of the response. Highest level of DNA expression
modulon
Highest level of DNA expression
modulon
refers to a set of genes expressed in response to
the specific environmental stimuli.
stimulon
Internal foldings within the cell structure of prokaryotes.
intermal membranes
- infoldings
of plasma membrane in prokaryotes
chromatophores
thylakoids
internal membrane that Gemmata obscuriglobus have
nucleoid membrane
internal membrane that magnetostatic bacteri have
magnetosomes
internal membrane that Chromatium vinosum have
chromosomes
internal membrane that Brocadia anammocidans have
anammoxosome
is a large compartment within anammox bacteria that performs anaerobic ammonium oxidation (anammox).
annamoxasome
annamox is also known as
anaerobic ammonium oxidation
internal membrane that Nitrosococcus oceani have
ammonia oxidizing membrane
internal membrane that Nitrobacter winogradski have
membranes at the pole
For microbial growth, ATP must be produced, and
there are three major mechanisms for producing
ATP in biological systems
oxidative phosphorylation
substrate level phosphorylation
photophosphorylation
s only for anaerobic organism
glycolysis
Uses organic compounds synthesized by microorganisms, plants, or animals
as a source of carbon and energy.
heterotrophs
general group that are heterotrophs
fungi
protozoans
- Have the enzymatic capability of utilizing glucose.
heterotrophs
Extracellular enzymes degrade polymeric structures into small molecules that
readily traverse the cell wall and are taken up by specific transporter systems
heterotrophs
- It is an organism that is able to use inorganic reduced compounds as a
source of energy (this mode of metabolism is known as
chemolithotrophy)
chemolitotrophs
- Electron flow proceeds from an electron donor to an electron acceptor,
and microorganisms interface with the redox reactions to couple
physiological activities
chemolitotrophs
- It is an organism that can use visible light as a primary energy source
for metabolism (a process known as photosynthesis).
phototrophs
They use the energy from light to carry out various cellular metabolic
processes
phototrophs
