1. Bacteria1 Ribosome Cytoplasm Nucleoid Glycocalyx Cell wall Cytoplasmic membrane Flagellum Inclusions Prokaryotic Cell Structure Chapters 3 and 11 Eukaryotic cell structure -- you should review from Biol 131 Archeal cell structure – not much different than Bacteria Bacterial Classification -- you are not responsible for the details presented in Chapter 11, but should read about different types of bacteria presented in class We will be discussing classification again as part of bacterial metabolism

2. Bacteria2 Why are bacteria so small? Size affects ‘surface to volume’ ratio Advantages of large S/V: diffusion rates metabolic rates reproductive rates Limits to size reduction? ‘defective’ bacteria Really big bacteria? -- Epulopiscium fishelsoni Epulopiscium web site http://www.micro.cornell.edu/cals/micro/research/labs/ angert-lab/epulopiscium.cfm

3. Bacteria3 Classification of bacteria is ‘murky’ A “Muddle in the Middle” Few distinctive characteristics Genetically promiscuous -- “horizontal” gene transfer Traditional classification: anatomical features staining characteristics metabolic properties Newer approach Genetic analysis Bergey’s manual is the ‘Bible’

4. Bacteria4 Classification based upon anatomical features 3 common shapes -- coupled with staining properties e.g., “Gram-pos cocci” “Gram-neg bacilli” Some unusual shapes also:

5. Bacteria5 Classification based upon anatomical features -- more info about these is in Chap 11 Other unusual bacteria Spirochetes Cell wall-less (mycoplasmas) Stalked Filamentous Myxobacteria fruiting bodiesStreptomyces

6. Bacteria6 External Anatomical Structures -- Bacterial Flagella Prokaryotic vs eukaryotic Arrangements monotrichous lopho- amphi- peri- How do we know movement is rotational? Flagella movement Flagella Details

7. Bacteria7 How do flagellated bacteria move? ‘Run and Tumble’ pattern Bacterial movement Chromatium motility Chromatium motility

8. Bacteria8 Spirochetes -- very strange structure -- e.g., Borrelia, Treponema Axial filaments Outer sheath Motility Spirochetes Borrelia Movement

9. Bacteria9 Fimbriae and Pili Fimbriae adhesion to surfaces Pili (pilus) genetic recombination other functions?

10. Bacteria10 The glycocalyx Functions Biofilms -- adherence -- virulence Prevent desiccation Composition Capsule layers vs Slime layers “xantham gum”(Xanthomonas) S. Pneumo evasion

11. Bacteria11 Cell wall structure Hans Christian Gram -- 1884 -- Crystal violet Gram positive structure -- thick layer of peptidoglycan Gram negative structure -- inner vs outer membranes -- thin layer of peptidoglycan -- lipopolysaccharides and endotoxins Acid fast staining -- Mycobacterium Lipopolysaccharide (LPS) layer Outer membrane Peptidoglycan Cell membrane Effect of penicillin

12. Bacteria12 Cell Membrane Structure Review basic membrane structure from Biol 131 -- Phospholipid bilayers -- Membrane proteins -- Membrane fluidity Membranes of thermophilic archaebacteria

13. Bacteria13 Components of prokaryotic cytosol No membrane-bound organelles Cytoplasm Ribosomes DNA Inclusions food or waste storage

14. Bacteria14 Endospores Clostridium & Bacillus Formation and regrowth Special properties? -- desiccated -- DNA binding proteins -- Ca-dipicolinic acid Magnetotactic bacteria -- possess magnetosomes Endospore formation Magnetotactic Bacteria