Bacterial Cell Inclusions and endospores Flashcards
inclusions
-prokaryotic cells
-bodies or aggregates within a cell
-often related to storage of a substance
microcompartments
-protein shells that encase specific enzymes/metabolites/cofactors that carry out specific metabolism
-some bacteria have
-carboxysomes concentrate enzymes involved in carbon CO2 fixation - increase effieicnyc and reduces unwanted side reactions
-other microcompartments protect cell against toxic reactive intermediates or bi-products
-e.g propionaldehyde is a toxic intermediate in propanediol metabolism and is enclosed in microcompatments
carbon storage polymers
-bacteria and other microbes store carbon when times are good to be accessed when times are bad in large granules
-diverse prokaryotes store carbon as lipids known as polybetahydroxyalkonoates (PHA) - most commone (poly beta hydroxybuterate)
-granules/polymers broken down for carbon energy when needed
other storage gtanules
-similar storage granules are produced by select microbes that store other nutrients/molecules
-polyphosphate granules for inorganic phosphate, which was broken down to produce biomolecules
-sulfur storage granules produced by bacteria and archea that oxidize reduced sulfar compounds for energy
gas vesicles
-some bacteria and archea can float because they produce gas vesucles
-protein structures that keep water and solutes out but gas in
-buoyancy to bring microbes to a favourable environment
-cyanobacteria blooms at the surface of water where sunlight is more intense and photosynthesis is then more efficient
endospores
-highly differentiated, dormant cells that can survive starvation and very harsh environmental conditions
-only produced by phylum firmicutes (gram positive)
-much more resistant than other kinds of bacterial spores
-extremely resistant to lots
-can survive hundreds of years or more and then germinate and grow again
vegetative cells
-metabolically active growing and dividing cells
when do vegetative cells differentiate into endospores
upon nutrient deprivation
-when the environment becomes more favourable the spore can be activated, germinate and return to the vegetative state
-sensors can detect nutrients and tell them to wak eup
endospores features
-metabolism and cell activities shut off
-provide resistance and stability
features that create a stable and resistant core
-dehydration
-dipicolinic acid
-small acid soluble proteins
dehyrations role in creating a stable and resistant core
-water goes from over 8-% to less than 25% increases resistance to dessication, heat, chemicals and inactivates cells enzymes
dipicolinic acids role in creating a stable and reistsant core for endospores
-unique to spores
-complexed with calcium ions
-important for dehydration process, also binds ad stabalized DNA
small acid soluble proteins role in reating a stable and resistant core
-only maxe during sporulation
-bind DNA and help make it more compact and protect it from damage
-also act as carbon/energy source during germination and outgrowth
endospore structure
-where DNA/ribsomes are housed 9BECOMES THE VEGETATIVE CELL)
-cortex - peptidoglycan layer
-two membranes - the outer membrane has no LPS therefore nothing like gram negative OM
-coat - protective protein layer comprised of many different proteins
major events in endospore formation
