12. 12
CytoplasmCytoplasm
Oxidative phosphorylation occurs at cell membrane
(since there are no mitochondria).
Cell membrane
The cell wall is outside of cell membrane
– rigid, protecting cell from osmotic lysis.
Cell Wall
17. 17
FLAGELLAFLAGELLA
• Some bacteria are motileSome bacteria are motile
• Locomotory organelles- flagellaLocomotory organelles- flagella
• Taste environmentTaste environment
• Respond to food/poisonRespond to food/poison
– chemotaxischemotaxis
18. 18
• Flagella
– embedded in cell membraneembedded in cell membrane
– project as strandproject as strand
– Flagellin (protein) subunitsFlagellin (protein) subunits
– move cell by propeller like actionmove cell by propeller like action
19. 19
Axial filamentsAxial filaments
– spirochetesspirochetes
– similar function to flagellasimilar function to flagella
– run lengthwise along cellrun lengthwise along cell
– snake-like movementsnake-like movement
20. 20
Making Wall-less FormsMaking Wall-less Forms
• Result from action of:Result from action of:
– enzymes lytic for cell wallenzymes lytic for cell wall
– antibiotics inhibiting peptidoglycan biosynthesisantibiotics inhibiting peptidoglycan biosynthesis
• Usually non-viableUsually non-viable
• Wall-less bacteria that don’t replicate:Wall-less bacteria that don’t replicate:
– spheroplasts (with outer membrane)spheroplasts (with outer membrane)
– protoplasts (no outer membrane).protoplasts (no outer membrane).
• Wall-less bacteria that replicateWall-less bacteria that replicate
– L formsL forms
22. 22
Pili (fimbriae)Pili (fimbriae)
• hair-like projections of the cellhair-like projections of the cell
• sexual conjugationsexual conjugation
• adhesion to host epitheliumadhesion to host epithelium
23. 23
Capsules and slime layersCapsules and slime layers
• outside cell envelopeoutside cell envelope
• well defined: capsulewell defined: capsule
• not defined: slime layer or glycocalyxnot defined: slime layer or glycocalyx
• usually polysaccharideusually polysaccharide
• often lost duringoften lost during in vitroin vitro cultureculture
• protectiveprotective in vivoin vivo
24. 24
Endospores (spores)Endospores (spores)
• Dormant cellDormant cell
• Produced when starvedProduced when starved
• Resistant to adverse conditionsResistant to adverse conditions
- high temperatures- high temperatures
- organic solvents- organic solvents
• contain calcium dipicolinatecontain calcium dipicolinate
• BacillusBacillus andand ClostridiumClostridium
