2.7 Flashcards
(29 cards)
inclusions
-bodies or aggregates within cell
-often related to storage of substance
microcompartments
-protein shells than encase specific enzymes/ metabolites / cofactors
-carry out specific metabolism
-analogous to organelle
what type of cells can have microcompartments
bacterial
what type of cells can have inclusions
prokaryotic cells
what do some prokaryotes store as carbon
-poly-beta-hydroxyutyric acid (PHB)
stored as lipids (PHA)
PHB
produced when excess of carbon / energy
it aggregates and forms large granules which can be broken down when needed
where is excess inorganic phosphate stored
polyphosphate granules, broken down to nucleic acids and phospholipids
sulfer storage granules
produced by bacteria and archaea that oxidize reduced sulfer compounds for energy
bacteria/ arch that can float produce
gas vessicles
gas vessicles
protein structures that keep water and solutes out but let gas in
confer buoyency
example of bacteria that uses gas vessicles
cyannobacteria
what is a type of microcompartment
Carboxysomes
Carboxysomes
-concentrate enzymes involved in carbon fixation\
-it increases their efficiency and reduces unwanted side reactions
what can microcompartments other than corboxysomes do?
protect cell against toxin/ reactive intermediates or biproducts
endospore
highly differenciated dormant cells that can survive starvation and very harsh envir conditions
what phylum produce endospores
what gram
firmicutes - gram +ve
how long do endospores survive
hundreds of years and then geminate
vegetative cell
growing and divide normally and differenciate into endospores upon nutrient deprivation
endospore features
they provide resistance and stability and shut down metabolism
how do endospores create stable and resistant core
dehydrate the core, use specific acid
also use SASPs to make the endospore more compact
what acid is used in the dehydration process
dipicolinic acid (DPA)
SASPs
small acid soluble proteins
-made during sporulation, make cell more compact and protect from damage
-used as carbon and energy source during germination
endospore structure
core
cortex
two membranes
coat
some spores have exosporium
core
-where DNA and ribosomes are housed
-becomes vegitative cell