The general structure of bacteria

Transcription

1 The general structure of bacteria

2 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

3 General structure of a bacteria

4 Electron micrography of a bacteria cell

5 The structure of an eucaryotic cell

6 Comparison of prokaryot og eucaryot cells size Nuclear membrane Chromosomes Nucleosomes Ribosomes Mitochondria Golgi apparat Endoplasmatic reticulum Flageller Procaryote 1-10µm mangler single circular lacking relatively small lacking lacking lacking without microtubuli Eucaryote µm present several linear attached to chromosomes relatively large present present present with microtubuli

7 Common structures bacteria cell Flagel Pili F or sex pili Capsule Cell wall Cytoplasmic membrane Ribosomes Inclusions Chromosomes Plasmids Function movement attachment, protection transfer DNA under conjugation attachment to surfaces, protection against phagocytosis protect, give form, stability permeabilitets barriere, transport, energy, enzymes make synthesis of proteins reservelager for næringsstoffer genetic material extrachromosomal DNA Kemisk opbygning protein protein protein polysaccharides peptidoglycan RNA, protein carbohydrate, lipid, protein, salts DNA DNA

8 Flagella og pili hos en peritrik bevægelig bakterie

9 Flagel typer

10 Flagella of (a) Bacillus cerius, (b) Vibro cholerae and (c) Bacillus brevis stained with flagel staining

11 Sex-pili

12 Electron micrography of flagella in Salmonella

13 The function af pili/fimbriae in different bactaria E. coli (alm. pili) E. coli (F-pili) N. gonorrhoeae Streptococcus pyogenes (fimbriae and M-protein) Ps. aeruginosa No ? Function attach til mucous epithelial cells in the intestinal tract transfer DNA during conjugation attach til mucous epithelial cells in the uro-genital tract attach til mucous epithelial cells, protect against phagocytosis, antigen variability attach til mucous epithelial cells

14 Electron micrography of fimbriae and pili

15 Mucoid colonies produced by abundant capsular production

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

17 Peptido-glycan layer

18 Peptidoglycan monomer

19 Function of cytoplasmic membrane 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

20 Bacillus cereus with endospore

21 Electron micrography of endospore

22 Difference between vegetative cell and endospore Surface microscopic appearance Enzymes Synthesis of macromolecules Heat resistant Resistance against chemicals and acids Resistance against radiation Lysozyme Metyleneblåt farve Vegetativ celle Gram-positive cell wall Non-refractive present present low low low sensitive sensitive Endospore thick spore layer and peptidoglycan wall refractive lacking lacking high high high resistant resistant

23 Different types og spores seen by light microscopy

24 Bacteriophage transfer its genetic material (DNA) into the bacteria

25 Electron micrography of a bacteriophage

26 A bacteriophage seeks out a bacteria

27 The bacteriophage inject its genetic material into the bacteria

28 The bacteria is destroyed due to the attach of a lysogenic bacteriofage