1. The Microbial World

2. Tree of Life Phylogeny based on 16S ribosomal DNA. Three domains of living organisms Borderline entities –Viruses –Viroids –Prions

3. Characteristics of Living Organisms Metabolism Growth Reproduction

4. Characteristics of Cells Cell membrane separates cell from outside DNA as genetic material Ribosomes Basic structural macromolecules Regulate flow of materials in and out Reproduce and are the result of reproduction Require energy

5. Types of Cells Prokaryotes Eukaryotes

6. Generally eukaryotic cells are morphologically complex and biochemically simple; prokaryotic cells are morphologically simple and biochemically complex

7. Prokaryotic Cell (Minimal) No “true” nucleus No internal membrane bound organelles

8. Prokaryotic Cell (Maximal) Inclusions External structures for attachment, genetic exchange, and movement

9. Prokaryotic Cell Wall Unique chemical composition Protects cell from osmotic lysis Two major types –Gram positive –Gram negative

10. Gram Negative Cell Walls

11. Gram Positive Cell Walls

12. Structures Exterior to the Wall

13. Glycocalyx/Capsule Extracellular polymer Important in attachment to surfaces - biofilms Protects against phagocytosis

14. Biofilm Formation

15. Pili Short hairlike appendages projecting from the bacterial cell surface Composed of protein Function: –Attachment –Transfer of DNA

16. Flagella Long protein (flagellin) appendage Motility Structure and function like a propeller Arrangement of flagella sometimes used in taxonomy/identification of bacteria

17. Cell Membrane Fluid Mosaic Model Phospholipid bilayer with embedded proteins Regulates transport of substances into and out of the cell

18. Membrane Transport Diffusion Passive/Facilitated Transport Group Translocation Active Transport

19. Internal Structures

20. Nucleoid Bacterial chromosome Single circular piece of DNA No associated histones

21. Plasmids Extrachromosomal small piece of DNA Independent of chromosome Code of ancillary functions –Antibiotic resistance –Metal resistance –Catabolic pathways Self-replicating Used in genetic engineering

22. Ribosomes Combinations of protein and RNA Essential structures Function –Protein synthesis –Expression of genetic information Size differs between prokaryotes and eukaryotes Prokaryotes: 70S

23. Inclusions Magnetosomes Poly-  hydroxybutyrate Sulfur granules Glycogen Polyphosphate granules