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LPS
- lipopolysaccharides.
- -highly cariable O- polysaccharide side chains
- -conserved lipid A (toxic)
- -acts as endotoxin (fever inducing)
- -fatty acids are esterified to glucosamine, one of them attach to core polysaccaride (sugar that extends outside cell)
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S-Layer
- composed of symmetrical hexagon protein subunits
- -protection
- -molecular sieve
- -1st described in archaea
- -recently discovered in G+ bacteria
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CAPSULE
- -most exterior layer
- -predominantly made from organized carbohydrate: heat labile (sometimes made from protein -eg: bacillus anthracis)
- -protective (antiphagocytic)
- -related structures which serve more for attachment (slime - loose network; glycocalix - very fine network)
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Mycobacterial envelope structure
- -Galactan
- -Arabinan
- -Mycolic acids: waxy surface
- -outer bilayer with phenolic glycolipids
- -capsule with loosely associated phospholipids &phenolic lipids
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contents of cytoplasmic
- -cytoplasmic skeleton
- - nucleoid
- -plasmids
- - ribosomes
- -specialized structures
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Bacterial skeleton
- -determines cell shape
- -CreS "Crescentin" (surves innser side of crescent shaped bacteria)
- -FtsZ (forms a 'Z ring' essential for cell septation; analog to tubulin)
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Bacterial Nucleoid
- single loop of double-stranded DNA
- (single molecule of DNA; ~4 x 106 bp in many bacteria ; complacted via super coiling)
- -attached to cell envelope (no membrane separates DNA from cytoplasm; replicates once for each cell division)
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Gene Expression
- RNA plymerase transcribes DNA to mRNA
- -Ribosome translates RNA to protein
- ----processes occur simultaneously
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intracellular structures related to photosynthesis
- cyanobacteria have thylakoids
- -carboxysomes fix carbon
- -other bacterial photosynthetic pigments
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cyanobacteria with thylakoids.
- -extensively folded inner membrane
- -contain chlorophyll
- -ancestor of chloroplasts
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carboxysomes fix carbon.
use energy to make sugar
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physobilisome proteins
collect light energy
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storage granules
intercellular desporits of material
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PHB - fatty acid polymer
for energy
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polyphosophate
to store material
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cell appendages
- -proteins
- -pili
- -fimbria
- -flagella
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cell attachment
- fimbriae, pili; for bacterial pathogencity
- -stalks attach cells to surfaces, extension of cell cytoplasm
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