The general structureof bacteria

The uni-cellular organisms Viruses

– Herpes virus, HIV, influenza virus

The procaryotic organisms– Escherichia, Salmonella, Pseudomonas

– Streptococcus, Staphylococcus, Neisseria

The eucaryotic organisms– Candida, Aspergillus, Trichophyton

– Entamoeba, Giardia, Plasmodium, Balantidium

General structure of abacteria

Electron micrography of abacteria cell

The structure of an eucaryotic cell

Comparison of prokaryot og eucaryot cells

with microtubuliwithout microtubuliFlageller

presentlackingEndoplasmaticreticulum

presentlackingGolgi apparatpresentlackingMitochondria

relatively largerelatively smallRibosomes

attached to chromosomes

lackingNucleosomesseveral linearsingle circularChromosomes

presentmanglerNuclear membrane10-100 µm1-10µmsize

EucaryoteProcaryote

Common structures bacteria cell

proteintransfer DNA under conjugation

F or sex pili

DNAextrachromosomal DNAPlasmidsDNAgenetic materialChromosomes

carbohydrate, lipid, protein, salts

reservelager for nærings-stoffer

InclusionsRNA, proteinmake synthesis of proteinsRibosomes

permeabilitets barriere, transport, energy, enzymes

Cytoplasmicmembrane

peptidoglycanprotect, give form, stabilityCell wall

polysaccharidesattachment to surfaces, pro-tection against phagocytosis

Capsule

proteinattachment, protectionPiliproteinmovementFlagelKemisk opbygningFunction

Flagella og pili hos en peritrikbevægelig bakterie

Flagel typer

Flagella of (a) Bacillus cerius, (b) Vibro cholerae and (c)

Bacillus brevis stained withflagel staining

Sex-pili

Electron micrography of flagella in Salmonella

The function af pili/fimbriaein different bactaria

attach til mucous epithelial cells10-20Ps. aeruginosa

attach til mucous epithelial cells, protect against phagocytosis, antigen variability

?Streptococcuspyogenes (fimbriaeand M-protein)

attach til mucous epithelial cellsin the uro-genital tract

100-200N. gonorrhoeae

transfer DNA during conjugation1-4E. coli (F-pili)

attach til mucous epithelial cellsin the intestinal tract

100-200E. coli (alm. pili)

FunctionNo.

Electron micrography of fimbriae and pili

Mucoid colonies produced by abundant capsular production

Cell surface of Gram-positive, Gram-negative and acid-fast

bacilli

Peptido-glycan layer

Peptidoglycan monomer

Function of cytoplasmicmembrane

serve as– an osmotic and permeability barrier

provide place for– transport system for specific substances– specific enzyme systems

provide energi to the cell owing to – respiratory and photosyntetic electron

transport systems synthesize cell wall components

– peptidoglycan, lipids and proteins coordinate

– the replication and separation af DNA– formation of septum and cell division

provide chemotaxi

Bacillus cereus with endospore

Electron micrography of endospore

Difference between vegetative celland endospore

resistantsensitiveMetyleneblåt farveresistantsensitiveLysozyme

highlowResistance againstradiation

highlowResistance againstchemicals and acids

highlowHeat resistant

lackingpresentSynthesis of macromolecules

lackingpresentEnzymes

refractiveNon-refractivemicroscopicappearance

thick spore layer and peptidoglycan wall

Gram-positive cellwall

SurfaceEndosporeVegetativ celle

Different types og spores seen by light microscopy

Bacteriophage transfer its geneticmaterial (DNA) into the bacteria

Electron micrography of a bacteriophage

A bacteriophage seeks out a bacteria

The bacteriophage inject itsgenetic material into the bacteria

The bacteria is destroyed due to the attach of a lysogenic

bacteriofage