Ribosomes
composed of RNA and proteins, made up of large and small subunits, key player in translation to make proteins
differences between prokaryotic and eukaryotic ribosomes
functionally the same but structurally slightly different
granules
storage bodies, specialized granules for sugar/fat/phosphates, can also just store waste
Endospores
produced under threatening environmental conditions (sporulation), purpose is to protect and survive, they cannot reproduce but they can exist in the endospore state for years
Bacillus spp. and Clostridium spp.
can produce endospores
layers to an endospore
core, cell wall, cortex, spore coats, exosporium
core
DNA, ribosomes, granules
Cell wall
normal gram-positive peptidoglycan
cortex
thick layer of loosely cross-linked peptidoglycan (modified cell wall)
spore coats
highly cross-linked keratin proteins as well as other structural proteins
exosporium
not always present, varies in composition but mostly proteins and carbohydrates
endospore formation
cell begins to be depleted of nutrients, chromosome is duplicated and separated, cell is separated into sporangium and forespore, sporangium engulfs forespore, sporangium actively synthesizes spore layers around forespore, cortex and outer coat layers are deposited, mature endospore, free spore is released with loss of sporangium, germination occurs when conditions are favorable again
nucleoid
bacteria don’t have a nucleus, region of dense genomic DNA, prokaryotic genomes considered smaller than eukaryotic genomes
enzymes used in chromosome condensation
DNA gyrase, topoisomerase
scaffolding proteins
assist in condensing the chromosome provide a way to save space
CRISPR
clustered regularly interspaced short palindromic repeats, family of DNA sequences within prokaryotic genomes, flanked by viral DNA from previous infections
Cas
CRISPR associated genes/proteins, DNA endonuclease, uses crRNA to target specific complementary DNA sequences
CRISPR/Cas
bacterial “immune system”, has a memory that will destroy viral genomic material the bacterium has previous encountered
plasmids
small circular pieces of DNA, considered more fluid than chromosome, contains non essential genes that are only kept if advantageous, can combine with other DNA to form new plasmids
engineered plasmids
synthetically made or modified by scientists
colicin (Col) plasmids
code for bacteriocins
degradative plasmids
code for digestive enzymes
fertility (F) plasmids
code for conjugation genes
Virulence plasmids
code for genes important for pathogenicity
PAI
pathogenicity island, series of virulence genes
resistance (R) plasmids
code for resistance to antibiotics or other toxic chemicals