bacterial morphology con’t plasma (cytoplasmic) membrane
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BACTERIAL MORPHOLOGY BACTERIAL MORPHOLOGY CON’T Plasma CON’T Plasma
(cytoplasmic) membrane(cytoplasmic) membrane
Phospholipid Phospholipid bilayer (Self-bilayer (Self-
assembly)assembly)Two fatty acid tails Two fatty acid tails (hydrophobic)(hydrophobic)
Glycerol-Phosphate Glycerol-Phosphate head head (hydrophilic)(hydrophilic)
ProteinsProteins
•Integral proteinsIntegral proteins–TransportTransport
•Peripheral proteinsPeripheral proteins–Enzymes Enzymes
Plasma membrane Plasma membrane functions functions (BET)(BET)
•BarrierBarrier
•Energy productionEnergy production
•TransportTransport
Plasma membranePlasma membrane• Target for chemotherapy and disinfectionTarget for chemotherapy and disinfection
– Damage to the membrane by alcohols, quaternary ammonium (detergents) and Damage to the membrane by alcohols, quaternary ammonium (detergents) and polymyxin antibiotics causes leakage of cell contents.polymyxin antibiotics causes leakage of cell contents.•Disruption of phospholipidsDisruption of phospholipids•Selective permeability allows passage of some moleculesSelective permeability allows passage of some molecules
• Enzymes for ATP productionEnzymes for ATP production• Photosynthetic pigments on foldings called chromatophores or thylakoidsPhotosynthetic pigments on foldings called chromatophores or thylakoids
Transport across Transport across membranesmembranes• Simple diffusion:Simple diffusion: Movement of a Movement of a
solute from an area of high solute from an area of high concentration to an area of low concentration to an area of low concentration (often known as concentration (often known as passive transport)passive transport)
• Facilitative diffusion:Facilitative diffusion: Solute Solute combines with a transporter protein combines with a transporter protein in the membranein the membrane
Transport across Transport across membranes membranes
•Active (requires energy, Active (requires energy, usually from lower to usually from lower to higher concentration)higher concentration)
Passive transport across Passive transport across membranesmembranes
•Simple diffusionSimple diffusion
•Facilitated diffusion Facilitated diffusion (permeases)(permeases)
•OsmosisOsmosis
Osmosis Osmosis
Sugar or salt molecules(solute)
Semi-permeable membrane (only water flows)
• Liquids flow towards higher solute Liquids flow towards higher solute concentration (lower liquid concentration)concentration (lower liquid concentration)
Active transport across membranesActive transport across membranes • Group translocation Group translocation
–Substance is altered during transport Substance is altered during transport (metabolism-glucose-6-PO(metabolism-glucose-6-PO33) sugars are ) sugars are phosphorylatedphosphorylated
• Carrier proteinsCarrier proteins–Similar to facilitated diffusion, but needs energySimilar to facilitated diffusion, but needs energy
• Group translocation of substances requires a Group translocation of substances requires a transporter protein and PEP transporter protein and PEP (phosphoenolpyruvate)(phosphoenolpyruvate)
• Active transport of substances requires a Active transport of substances requires a transporter protein and ATPtransporter protein and ATP
Cytoplasm contentsCytoplasm contents
– Water, proteins, Water, proteins, carbohydrates, carbohydrates, lipids, inorganic lipids, inorganic ions, DNA, RNA and ions, DNA, RNA and inclusionsinclusions
Nuclear areaNuclear area
•No nuclear No nuclear membranemembrane
•ChromosomeChromosome
•Plasmid Plasmid
Bacterial plasmid
• Extrachromosomal genetic material
• Replicate independently
• Not crucial for survival (resistance, enzymes, etc)
RibosomesRibosomes
• Protein synthesisProtein synthesis
• Two subunits 30 and Two subunits 30 and 50 S = 70 S (rRNA)50 S = 70 S (rRNA)
• Target for antibiotic Target for antibiotic actionaction
InclusionsInclusions
•Reserve depositsReserve deposits
–lipids, sulfur, carboxysomeslipids, sulfur, carboxysomes
–Metachromatic granulesMetachromatic granules
–Polysaccharide granulesPolysaccharide granules
–GasGas
EndosporesEndospores– Only Gram-positivesOnly Gram-positives
•BacillusBacillus spp. spp.•ClostridiumClostridium spp. spp.
– Highly resistantHighly resistant– Spore coat has a form of Spore coat has a form of
dipicolinic acid and Cadipicolinic acid and Ca+ +
ions in itions in it
The eucaryotic cell The eucaryotic cell (cont.(cont.))
•Larger and more complex Larger and more complex than procaryotesthan procaryotes
•10 to 100 10 to 100 mm
•Membrane-bounded Membrane-bounded organellesorganelles
Flagella and CiliaFlagella and Cilia
• LocomotionLocomotion
• Flagella, few and Flagella, few and longlong
• Cilia, numerous Cilia, numerous and shortand short
Movement of eukaryotic Movement of eukaryotic flagella and ciliaflagella and cilia
• Respiratory systemRespiratory system
• Digestive systemDigestive system
• LocomotionLocomotion
Cell wall of eucaryotesCell wall of eucaryotes
• Not present in all eucaryotes Not present in all eucaryotes (alga, plants, some fungi)(alga, plants, some fungi)
• No peptidoglycanNo peptidoglycan
• Simpler than procaryotesSimpler than procaryotes
Cell wall of eucaryotes (Cell wall of eucaryotes (cont.cont.))
• CelluloseCellulose–Glucose polymerGlucose polymer
• Chitin (most fungi, some Chitin (most fungi, some protozoans)protozoans)–N-acetylglucosamine N-acetylglucosamine
polymerpolymer
Cell wall of eucaryotes Cell wall of eucaryotes ((cont.cont.))
•Polysaccharides (yeast)Polysaccharides (yeast)–GlucanGlucan–MannanMannan
Glycocalyx functionsGlycocalyx functions
•Strengthens the cell Strengthens the cell surfacesurface
•Helps attach cells Helps attach cells togethertogether
•Cell to cell recognitionCell to cell recognition•Sticky carbohydratesSticky carbohydrates
Eucaryotes plasma Eucaryotes plasma (cytoplasmic) membrane(cytoplasmic) membrane
•Similar to procaryotesSimilar to procaryotes–Receptor sites Receptor sites (carbohydrates) cell to cell (carbohydrates) cell to cell recognitionrecognition
Eucaryotes plasma Eucaryotes plasma (cytoplasmic) membrane (cytoplasmic) membrane (cont.)(cont.)
–Attachment sites for Attachment sites for bacteriabacteria
–Sterols (rigidity)Sterols (rigidity)–transport (passive and transport (passive and active)active)
Eucaryotes passive Eucaryotes passive transporttransport
•DiffusionDiffusion
•Facilitated diffusionFacilitated diffusion
•OsmosisOsmosis
Eucaryotes active transport Eucaryotes active transport (endocytosis)(endocytosis)
•Phagocytosis Phagocytosis (macrophages –cells are (macrophages –cells are “eating”)“eating”)
•Pinocytosis (extracellular Pinocytosis (extracellular fluid into the cell—cells fluid into the cell—cells are “drinking”)are “drinking”)
CytoplasmCytoplasm•CytoskeletonCytoskeleton
–MicrofilamentsMicrofilaments–Intermediate Intermediate filamentsfilaments
–MicrotubulesMicrotubules
Cytoplasm (Cytoplasm (cont.cont.))•Cytoskeleton functionsCytoskeleton functions
–ShapeShape–Movement Movement
•Entire cellEntire cell•Substances within the Substances within the cellcell
NucleusNucleus
•Spherical to ovalSpherical to oval•Contains DNA Contains DNA •combined with histones combined with histones •and nonhistonesand nonhistones
Nucleus (Nucleus (cont.cont.))
•Chromatin (threadlike)Chromatin (threadlike)–Non-reproducing cellsNon-reproducing cells
•Chromosomes (rodlike Chromosomes (rodlike structure)structure)–Reproducing cellsReproducing cells
Endoplasmic reticulum (ER)Endoplasmic reticulum (ER)• Network of sacsNetwork of sacs• Synthesis and storage Synthesis and storage
of lipids and proteinsof lipids and proteins
Endoplasmic reticulum (ER) Endoplasmic reticulum (ER) ((cont.cont.))
• Rough ER Rough ER –numerous ribosomes, protein numerous ribosomes, protein
synthesissynthesis• Smooth ERSmooth ER
–Lipid synthesis Lipid synthesis
Golgi ComplexGolgi Complex• Similar to ERSimilar to ER• Receives ER Receives ER
productsproducts– SortsSorts– packagespackages– delivers (secretory delivers (secretory
vesicles)vesicles)
MitochondriaMitochondria
• Double membraneDouble membrane– Multy-folded inner Multy-folded inner
membrane membrane
Mitochondria (Mitochondria (cont.cont.))
• Provides a large surface for Provides a large surface for proteins involved in cellular proteins involved in cellular respiration (ATP synthesis)respiration (ATP synthesis)
• Multiply on their ownMultiply on their own
ChloroplastChloroplast
• Algae and green Algae and green plantsplants
• ChlorophyllChlorophyll
• Photosynthesis Photosynthesis enzymesenzymes
• Multiply on their Multiply on their ownown
LysosomesLysosomes
• Derived from Golgi Derived from Golgi complexcomplex
• Free spheres in Free spheres in cytoplasmcytoplasm
• Contain powerful Contain powerful digestive enzymesdigestive enzymes
• Numerous in white Numerous in white blood cellsblood cells
VacuolesVacuoles• Storage of nutrientsStorage of nutrients
• Metabolic wastesMetabolic wastes
• WaterWater