1. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacteria Chapter 34 Copyright © McGraw-Hill Companies Permission required for reproduction or display

2. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies The Prevalence of Bacteria Bacteria are the oldest, structurally simplest, and the most abundant forms of life on earth.  Abundant for over 2 billion years before the appearance of eukaryotes.  5,000 different kinds currently recognized. - Based primarily upon their metabolic and genetic characteristics.  Can only be properly characterized on a defined medium.

3. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies The Prevalence of Bacteria Bacterial Form  Bacillus (Bacilli) straight and rod-shaped.  Coccus (Cocci) spherical shaped.  Spirillus (Spirilla) long and helical shaped. Copyright © McGraw-Hill Companies Permission required for reproduction or display

4. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies The Prevalence of Bacteria Prokaryotes versus Eukaryotes  Multicellularity  Cell Size  Chromosomes  Cell Division and Recombination  Internal Compartmentalization  Flagella  Metabolic Diversity

5. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies The Bacterial Surface Bacterial Surface  Cell wall maintains shape and protects the cell from swelling and rupturing. - Usually consist of peptidoglycan.  Gram Positive - Thicker peptidoglycan  Gram Negative - Thinner peptidoglycan  Flagella - Slender protein - locomotion  Pili - Hairlike structures - attachment  Endospores - Resistant to environment.

6. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Gram Stain Copyright © McGraw-Hill Companies Permission required for reproduction or display Copyright © McGraw-Hill Companies Permission required for reproduction or display

7. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies The Cell Interior Internal Membranes  Invaginated plasma membrane. Nucleoid Region  Lack nucleus - Genes encoded with single double-stranded DNA. Ribosomes Copyright © McGraw-Hill Companies Permission required for reproduction or display

8. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacterial Diversity Key Classification Characteristics  Photosynthetic or Nonphotosynthetic  Motile or Nonmotile  Unicellular or Multicellular  Spore Formation by Division or Transverse Binary Fission.

9. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacterial Diversity Comparing Archaebacteria and Eubacteria  Cell Wall - Archaebacteria lack peptidoglycan.  Plasma Membranes - Composed of different lipids.  Gene Translation Machinery - Archaebacteria similar to eukaryotes.  Gene Architecture - Eubacteria not interrupted by introns.

10. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacterial Variation Two Process create bacterial variation:  Mutation - Spontaneous errors in DNA replication.  Genetic Recombination - Occurs by gene transfer from one cell to another by viruses or conjugation.

11. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacterial Metabolism Autotrophs  Obtain carbon from inorganic CO 2. - Photoautotrophs - Sunlight - Chemoautotrophs - Inorganic Chemicals Heterotrophs  Obtain carbon from organic molecules. - Photoheterotrophs - Sunlight - Chemoheterotrophs - Organic Molecules

12. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Bacterial Metabolism How Heterotrophs Infect Host Organisms  Proteins secreted by Type III System. - May be used to transfer other virulence proteins into nearby eukaryotic cells.

13. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Human Bacterial Diseases Tuberculosis  Afflicts respiratory system and easily transmitted from person to person through the air. Dental Caries (cavities)  Tooth decay caused by bacteria present in plaque. - High sugar diets increase tooth decay.  Lactic acid bacteria ferment sugars and reduce pH, thus degenerating tooth enamel.

14. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Human Bacterial Diseases Sexually Transmitted Diseases  Gonorrhea (Neisseria gonorrhoeae)  Syphilis (Treponema pallidum)  Chlamydia (Chlamydia trachomatis) Copyright © McGraw-Hill Companies Permission required for reproduction or display

15. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Importance of Bacteria Largely responsible for creating atmospheric properties. Contribute to carbon balance. Nitrogen Fixation Industrial Processes  Fermentation of lactose into lactic acid. - Milk, Cheese, Yogurt Genetic Engineering Removal of environmental pollutants.

16. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies Copyright © McGraw-Hill Companies Permission required for reproduction or display